Acoustic notifications

ABSTRACT

Techniques for using beam-formed acoustic notifications for pedestrian notification are described. Computing device(s) can receive sensor data associated with an object in an environment of a vehicle. The computing device(s) can determine first data for emitting a first beam of acoustic energy via speaker(s) of an acoustic array associated with the vehicle, and second data for emitting a second beam of acoustic energy via speakers of the acoustic array. The computing device(s) can cause the speaker(s) to emit the first beam in a direction of the object at a first time and the second beam in the direction of the object at a second time. Directions of propagation of the first beam and the second beam are offset so that the object can localize the source the acoustic notification, thereby localizing the vehicle in the environment.

BACKGROUND

Vehicles can encounter many situations in which they should alertpersons, vehicles, and the like, of their presence in order to avert apotential collision or otherwise prevent the vehicle coming within anunsafe distance of an external object. As one example, a pedestrian whocrosses the road in front of the vehicle can be jaywalking or may not bepaying attention to the approach of the vehicle. The driver of thevehicle can use the vehicle's horn to alert the pedestrian. However, ahorn will typically have an acoustic radiation pattern that issub-optimal in that it may not be sufficient to warn the pedestrian thatthe horn being honked is intended for him/her. Instead, otherpedestrians or other drivers in the vicinity of the vehicle can believethe horn is being honked at them. Moreover, a pattern of the sound wavesemitted by the horn can make it difficult to localize the source of thehorn. From the perspective of the pedestrian, the horn can be perceivedas coming from another vehicle. Furthermore, the horn can cause thepedestrian to look in a direction other than the direction of thevehicle that generated the horn honk, thereby potentially distractingthe pedestrian from the actual source of the horn.

Additionally, electric vehicles can be difficult to audibly detect dueto low levels of emitted noise from an electric and/or hybrid propulsionsystem (e.g., lack of combustion engine noise and/or lower levels oftire noise) making it difficult for others to hear the vehicle as ittravels. Further, the reaction time required for a vehicle to generatean alert, and the reaction time of a person (or other vehicle) afterhearing the alert, are such that relying solely on outputting an alertto avert a potential collision or an approach of the vehicle within anunsafe distance of an external object is inadequate, especially for manyclose-encounter collision scenarios.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical components or features.

FIG. 1A illustrates an example vehicle that is associated with one ormore acoustic arrays in a linear array configuration.

FIG. 1B illustrates another example vehicle that is associated with oneor more acoustic arrays in an arbitrary array configuration.

FIG. 2 illustrates an example of using an acoustic array for emitting abeam of acoustic energy utilizing beam-formed audio.

FIG. 3A illustrates a perspective view of an example of outputting anacoustic notification to alert a pedestrian of a possible collision orunsafe proximity to a vehicle.

FIG. 3B illustrates a top view of an example of outputting an acousticnotification to alert a pedestrian of a possible collision or unsafeproximity to a vehicle.

FIG. 4 illustrates an example of using an acoustic array for emittingbeams of acoustic energy via multiple channels.

FIG. 5A illustrates an example of an acoustic notification that can beoutput via an acoustic array utilizing a multi-channel configuration.

FIG. 5B illustrates another example of an acoustic notification that canbe output via an acoustic array utilizing a multi-channel configuration.

FIG. 5C illustrates yet another example of an acoustic notification thatcan be output via an acoustic array utilizing a multi-channelconfiguration.

FIG. 5D illustrates another example of an acoustic notification that canbe output via an acoustic array utilizing a multi-channel configuration.

FIG. 6 illustrates an example of outputting an acoustic notification toalert a pedestrian, or other object, of a presence of a vehicle.

FIG. 7 illustrates a block diagram of an example system for facilitatingacoustic notifications.

FIG. 8 illustrates a flow diagram illustrating an example process forfacilitating acoustic notifications.

FIG. 9 illustrates a flow diagram illustrating an example process forcausing beams of acoustic energy to be emitted by speakers of anacoustic array for providing a beam-formed acoustic notification.

FIG. 10 illustrates a flow diagram illustrating another example processfor causing sounds to be emitted by speakers of an acoustic array for amulti-channel acoustic notification.

DETAILED DESCRIPTION

Techniques described herein are directed to using acoustic notificationsfor communicating information to objects in environments of autonomousvehicles. An autonomous vehicle can include acoustic arrays on one ormore exterior surfaces of the autonomous vehicle, which, at least insome examples, can be used to steer beams of acoustic energy (i.e.,acoustic beam steering). These acoustic arrays can have speakersconfigured to output beams of acoustic energy, which can providenotification to pedestrians, for instance of a presence of theautonomous vehicle or a potential collision. In at least one example,techniques described herein are directed to manipulating beam-formedaudio signals (e.g., moving a beam-formed audio signal side to side) insuch a way that a pedestrian (or other external object) proximate avehicle (e.g., an autonomous vehicle) can hear a sound (e.g., resultingfrom the speakers emitting the beam-formed audio signals) and canidentify a source of the sound. That is, the pedestrian (or otherexternal object) can engage stereoscopic hearing to localize thevehicle. Further, because autonomous vehicles lack human drivers toconvey intents (e.g., indications of what the driver is intending todo), in some examples, the acoustic array can emit sounds such that thepedestrian (or other external object) can additionally determine thebehavior of the vehicle based on the emitted sound.

Furthermore, in some examples, the acoustic arrays can be associatedwith multi-channel speaker configurations, wherein one or more speakersof an acoustic array can be associated with different channels.Techniques described herein are directed to sending different signals todifferent channels such that, when sounds are emitted by speaker(s)corresponding to the different channels (based on the differentsignals), a pedestrian (or other external object) can hear a sound thatis spatialized across a surface of a proximate vehicle (e.g., anautonomous vehicle). As a result, the pedestrian (or other externalobject) can identify a source of the sound (e.g., the autonomousvehicle) and can additionally determine a size of the vehicle (e.g.,width). In some examples, the pedestrian (or other external object) canfurther determine the behavior of the vehicle based on the spatializedsound.

Accordingly, techniques described herein enable pedestrians (or otherexternal objects) to identify a source of a sound (output by anautonomous vehicle) with more efficacy and safety than with existingtechniques. For instance, techniques described herein enable anautonomous vehicle to convey its position to objects in its environment,which enables pedestrians (or other external objects) to avert potentialcollisions or approaches of the autonomous vehicle within an unsafedistance. Furthermore, techniques described herein enable autonomousvehicles to be more easily audibly detectable, while reducing a volumeof the sound necessary for perceiving the sound. As such, techniquesdescribed herein are directed to increasing safety for autonomousvehicles, particularly for pedestrians or other external objects inenvironments of such autonomous vehicles.

FIG. 1A illustrates an example vehicle 100 that is associated with oneor more acoustic arrays 102. The example vehicle 100 shown in FIG. 1A isan automobile having four wheels. Other types and configurations ofvehicles are contemplated, such as, for example, vans, sport utilityvehicles, cross-over vehicles, trucks, buses, agricultural vehicles, andconstruction vehicles. The vehicle 100 can be powered by one or moreinternal combustion engines, one or more electric motors, hydrogenpower, any combination thereof, and/or any other suitable power sources.For the purpose of illustration, the vehicle 100 can be an autonomousvehicle configured to operate according to a Level 5 classificationissued by the U.S. National Highway Traffic Safety Administration, whichdescribes a vehicle capable of performing all safety-critical functionsfor the entire trip, with the driver (or occupant) not being expected tocontrol the vehicle at any time. In such an example, since the vehicle100 can be configured to control all functions from start to stop,including all parking functions, it can be unoccupied. This is merely anexample, and the systems and methods described herein can beincorporated into any ground-borne, airborne, or waterborne vehicle,including those ranging from vehicles that need to be manuallycontrolled by a driver at all times, to those that are partially orfully autonomously controlled. Additional details associated with thevehicle 100 are described below.

As described above, the vehicle 100 can include one or more acousticarrays 102, which can be associated with one or more exterior surfacesof the vehicle 100. While four acoustic arrays 102A-102N areillustrated, the vehicle 100 can include any number of acoustic arrays102. The acoustic arrays 102 need not be identical in configuration ordimensions. For instance, in at least one example, acoustic arrays 102Aand 102C can be shorter in length than acoustic arrays 102B and 102N, aswell as have differing number of speakers, placement of speakers, sizeof speakers, curvature, etc. In at least one example, an enclosure orother structure can house each of the acoustic arrays 102 and such anenclosure or other structure can be mounted on an exterior surface ofthe vehicle 100. In at least one example, the acoustic arrays 102 can bemounted (e.g., via a respective enclosure or other structure) to directtheir respective outputs outward into the environment within which thevehicle 100 is positioned, toward a location of an object targeted toreceive an acoustic notification. In at least one example, the vehicle100 can be bidirectional and as such, the acoustic arrays 102 may nothave a front or rear designation. Instead, depending on which directionthe vehicle 100 is driving, any acoustic array 102A-102N can be theacoustic array facing the direction of travel (and thus, the frontacoustic array at that time).

For the ease of illustration, a single acoustic array 102A is described,however, each acoustic array 102A-102N can have a same or similarstructure and/or perform the same or similar functions. The acousticarray 102A can include several speaker(s) 104, with each speaker in theacoustic array 102A being coupled with an output amplifier. Eachamplifier can include a gain input and a signal input.

The acoustic array 102A can include (or otherwise be associated with,e.g. from a remote system) one or more processors 106 (e.g.,microprocessor(s), digital signal processor(s) (DSP), etc.) that can beconfigured to receive data (e.g., signal(s), described below) andprocess the data to generate one or more sounds into an environmentwithin which the vehicle 100 is positioned. In at least one example, theacoustic array 102A can output one or more sounds such to form a beam ofsteered acoustic energy. While FIG. 1A illustrates that the processor(s)106 are associated with the acoustic array 102A, in an alternativeexample, the processor(s) 106 can be electrically coupled to any numberof acoustic arrays 102. Or, in an alternative example, the acousticarray 102A can be electrically coupled to other processor(s). Theprocessor(s) 106 can calculate data representing a gain for the gaininput of each amplifier and can calculate data representing a signaldelay for the signal input of each amplifier. The processor(s) 106 canaccess and/or or receive data (e.g., speaker data) representinginformation on the speaker(s) 104 (e.g., from an internal and/orexternal data source) and the information can include, but is notlimited to, array width, speaker spacing in the acoustic array 102A, awave length distance between adjacent speakers in the acoustic array102A, a number of speakers in the acoustic array 102A, speakercharacteristics (e.g., frequency response, output level per watt ofpower, etc.), etc.

The processor(s) 106 can implement function(s) 108 to operate theacoustic array 102A. The function(s) 108 can be implemented in hardware,software, or a combination thereof (e.g., processor(s) 106,computer-readable media executable by the processor(s) 106, ASICs,FPGAs, etc.), and the function(s) 108 implemented can include, but arenot limited to, a delay calculator, a gain calculator, a beam steeringalgorithm, an adaptive beam steering algorithm, an environmentcompensator, an audio signal modulator, an ambient noise compensator,and a signal converter. While the function(s) 108 are shown external tothe processor(s) 106, in an alternative example, one or more of thefunction(s) 108 can be integral to the processor(s) 106. In at least oneexample, the processor(s) 106 can access and/or receive speaker datawhich can be utilized in association with implementation of thefunction(s) 108.

In at least one example, data and signals received by the processor(s)106 can be converted from one format to another format using the signalconverter. For example, the signal converter can convert digital data toan analog signal using a digital-to-analog converter (DAC) and canconvert an analog signal to digital data using an analog-to-digitalconverter (ADC). In at least one example, processing of datarepresenting audio signal(s), data representing microphone signal(s),and data representing the environmental signal(s) can be handled in theanalog domain using the DAC, the digital domain using ADC, or both.

Data representing environmental signal(s) (e.g., from environmentalsensor(s)) and output data representing compensated environment data,such as the speed of sound (e.g., compensated for temperature, altitude,etc.), can be converted by the environment compensator for use by thebeam steering algorithms.

The ambient noise compensator can receive data representing ambientnoise (e.g., from a microphone) and process the data to output datarepresenting gain compensation. The data representing the gaincompensation can be indicative of ambient noise levels in theenvironment external to the vehicle 100. High levels of ambient noisecan require gain levels applied to the amplifiers in one or morechannels to be increased to compensate for the high levels of ambientnoise. The gain calculator can receive the data representing gaincompensation and can increase gain or decrease gain in one or more ofthe channels of the acoustic array 102A. Additionally, or alternatively,one or more algorithms can be used to perform frequency analysis (e.g.,a Fourier analysis) to determine which frequencies are prevalent in anenvironment such that frequencies which are less prevalent (e.g., havinglower relative power in a Fourier analysis) may be used for acousticemissions from the acoustic array 102A.

The acoustic array 102A can receive data representing an audio signaland data representing a modulation signal (e.g., from a microphone orfrom another audio signal) and can modulate the data representing theaudio signal using the data representing the modulation signal via audiosignal modulation. For example, the data representing the modulationsignal can be based on regenerative braking noise generated by a drivesystem of the vehicle 100. A signal from a microphone can be the signalsource for the data representing the modulation signal, and an amplitudeof the data representing the modulation signal can be used to modulatethe data representing the audio signal (e.g., from a digital audiofile). The audio signal modulator can process the data representing theaudio signal and data representing the modulation signal in the analogdomain (e.g., using DAC in the signal converter) or the digital domain(e.g., using ADC in the signal converter).

The gain calculator and the delay calculator can calculate channel gainsand channel delays for the acoustic array 102A using algorithms specificto the type of beam steering algorithm being implemented for theacoustic array 102A, such as for the beam steering algorithm or theadaptive beam steering algorithm, for example. Additional detailsassociated with the beam steering algorithm and the adaptive beamsteering algorithm are described in U.S. Pat. No. 9,878,664, issued onJan. 30, 2018, entitled “Method for Robotic Vehicle Communication withan External Environment via Acoustic Beam Forming,” the entire contentsof which are hereby incorporated by reference. In some examples, thegain calculator and the delay calculator can determine data foroutputting an acoustic notification that is perceived as moving from afirst side to a second side. In at least one example, the gaincalculator and the delay calculator can determine data for steering anacoustic beam from a first angle to a second angle (e.g., sweeping). Inadditional or alternative examples, during sweeping, a combined signal(i.e., a sum of the acoustic notification at the first angle and thesecond angle) may be input into a windowed high pass filter and anamplitude of the filtered signal may be smoothly varied from a maximumamplitude to a minimum amplitude and back during the transition. Such aprocess can be utilized to remove any artifacts (e.g., pops, clicks,scratches, etc.) associated with sweeping.

In at least one example, the processor(s) 106 can receive data, asdescribed below, and generate one or more channels of gain and one ormore channels of delay for the acoustic array 102A. In at least oneexample, the gain calculator can implement array shading by adjustingthe gain (G_(e)) applied to amplifiers coupled to speaker(s) 104 at edgeportions of the acoustic array 102A to be less than a gain (G_(m))applied to amplifiers coupled to speakers at middle portions of theacoustic array 102A. For example, after applying array shading, the gainat middle portions of the acoustic array 102A (G_(m)) is greater thanthe gain at the edge portions of the acoustic array 102A (G_(e)).Speaker position accessed from speaker data can be used to determinewhich speaker positions in the acoustic array 102A have the edge gain(G_(e)) applied to their amplifiers and which positions in the acousticarray 102A have the middle gain (G_(m)) applied to their amplifiers. Forinstance, if the acoustic array 102A has 32 speaker(s) 104 such thatthere are 32 speaker positions, then eight speakers at each edge portioncan have the edge gain (G_(e)) applied to their respective amplifiersand 16 speakers at the middle portion can have the middle gain (G_(m))applied to their respective amplifiers. The middle gain (G_(m)) can varyamong the speaker(s) 104 in the middle portion. The edge gain (G_(e))can vary among the speaker(s) 104 in the edge portions.

In at least one example, the acoustic array 102A can have a closed-formsolution for delays and gains for each speaker so as to create a beam ofacoustic energy in a particular direction (e.g., at a user specifiedangle with respect to the array), such as a linear array with fixedspacing between individual speakers, as illustrated in FIG. 1A.Techniques described above with respect to adding time delays to anaudio signal at individual speakers are directed to closed-formsolutions.

However, in alternative examples where an arbitrary acoustic array isutilized, generating acoustic array can have a non-closed form solution.An arbitrary array can include a linear array, a curved array, etc.,wherein such arrays may or may not have non-uniform spacing betweenspeakers, differing sizes of speakers, and the like. An example of acurved, arbitrary array is shown as the acoustic array 102A in FIG. 1B.With respect to such arbitrary acoustic arrays, simple geometry cannotbe used to determine what time delays should be added at individualspeakers to create the beam steering effect. As such, techniques can beused to estimate time delays based on far-field summations forindividual beam angles and use such estimates to determine arepresentative pattern of non-closed-form solution array pattern forarbitrarily spaced (e.g., non-linear) elements (e.g., which may beaccomplished in simulation). Furthermore, in at least one example, theacoustic array 102A in FIG. 1B can use amplitude tapering (i.e.,reducing a signal amplitude as speaker position is further from a centerof the array) to enhance the performance of non-closed-form solutionarray patterns. Such a tapering may result in a linear, polynomial,exponential, or otherwise decay of a signal amplitude with respect acenter speaker of the acoustic array. In at least one example, theacoustic array 102A in FIG. 1B can utilize the function(s) 108 describedabove; however, the function(s) 108 can additionally include Lagrangefilter coefficients as applied to gains and a taper function (e.g.,Nuttall), which can be centered in a direction of a beam, to determinetime delays for outputting audio signals.

FIG. 2 illustrates an example of using an acoustic array, such as theacoustic array 102A, for emitting a beam of acoustic energy usingbeam-formed audio.

In at least one example, the vehicle 100 can be associated with one ormore sensor system(s) 200 that can be disposed on the vehicle 100. Theone or more sensor system(s) 200 can include light detection and ranging(LIDAR) sensors, radio detection and ranging (RADAR) sensors, ultrasonictransducers, sound navigation and ranging (SONAR) sensors, locationsensors (e.g., global positioning system (GPS), compass, etc.), inertialsensors (e.g., inertial measurement units, accelerometers,magnetometers, gyroscopes, etc.), cameras (e.g., RGB, IR, intensity,depth, etc.), wheel encoders, microphones, environmental sensors (e.g.,temperature sensors, humidity sensors, light sensors, pressure sensors,etc.), etc. The one or more sensor system(s) 200 can generate sensordata 202, which can be utilized by vehicle computing device(s) 204onboard the vehicle 100.

Furthermore, in at least one example, the vehicle computing device(s)204 can include one or more systems, including, but not limited to, alocalization system 206, a perception system 208, a planning system 210,and an audio output determination system 212.

In at least one example, the localization system 206 can determine apose of the vehicle 100 (e.g., position, orientation, etc.) and/ordetermine where the vehicle 100 is in relation to a local and/or globalmap based at least in part on sensor data 202 received from the sensorsystem(s) 200 and/or map data associated with a map. A map can be anynumber of data structures modeled in two dimensions or three dimensionsthat are capable of providing information about an environment, such as,but not limited to, topologies (such as intersections), streets,mountain ranges, roads, terrain, and the environment in general.

In at least one example, the perception system 208 can perform objectdetection, segmentation, and/or classification based at least in part onthe sensor data 202 received from the sensor system(s) 200. Forinstance, in at least one example, the perception system 208 canidentify other objects, such as a pedestrian, a cyclist, anothervehicle, etc., in the environment within which the vehicle 100 ispositioned. Furthermore, the perception system 208 can track one or moreof a pose of other objects (e.g., position, orientation, etc.) or avelocity of other objects in the environment.

In at least one example, the planning system 210 can determine routesand/or trajectories to use to control the vehicle 100 based at least inpart on the sensor data 202 received from the sensor system(s) 200. Inat least one example, the planning system 210 can include a predictionsystem that can predict the behavior of other objects in the environmentwithin which the vehicle 100 is positioned based at least in part onsensor data 202 received from the sensor system(s) 200.

Additional details of localization systems, perception systems, and/orplanning systems that are usable can be found in U.S. Pat. No.9,612,123, issued on Apr. 4, 2017, entitled “Adaptive Mapping toNavigate Autonomous Vehicle Responsive to Physical Environment Changes,”and U.S. patent application Ser. No. 15/632,208, filed Jun. 23, 2017,entitled “Trajectory Generation and Execution Architecture,” both ofwhich are incorporated herein by reference, in their entirety. In anexample where the vehicle 100 is not an autonomous vehicle, one or moreof the aforementioned systems can be omitted from the vehicle 100.

The audio output determination system 212 can facilitate broadcastingacoustic notifications (e.g., acoustic notifications) into theenvironment external to the vehicle 100 using the acoustic arrays 102.In at least one example, the audio output determination system 212 canbe configured to determine when to send a signal 214 (e.g., a controlsignal) to the one or more acoustic arrays 102. In at least one example,the signal 214 can be associated with a trigger signal and can includedata such as an audio signal selected, directions of propagation foremitting one or more beams of acoustic steered energy, and/or a timingfor emitting the one or more beams of acoustic steered energy. In atleast one example, the signal 214 can further include modulation signaldata received by acoustic arrays 102. Additional details are describedbelow with reference to FIGS. 3A and 3B.

The audio output determination system 212 can send the signal 214 to anacoustic array 102A to activate the acoustic array 102A. In at least oneexample, the audio output determination system 212 can send the signal214 to the acoustic array that is positioned approximately in thedirection of a target object (e.g., if the target object is in front ofthe vehicle 100, the audio output determination system 212 can send asignal 214 to the acoustic array 102A). As described above, in at leastone example, the acoustic array 102A can include one or more processors106 (e.g., microprocessor(s), digital signal processor(s) (DSP), etc.)that can be configured to receive the signal 214 and process the data togenerate, using the acoustic array 102A, signals which can be output asa beam of steered acoustic energy 216 into an environment within whichthe vehicle 100 is positioned.

The acoustic array 102A can include several speaker(s) 104, with eachspeaker in the acoustic array 102A being coupled with an outputamplifier. Each amplifier can include a gain input and a signal input.The processor(s) 106 can perform function(s) 108 to calculate datarepresenting a gain for the gain input of each amplifier and cancalculate data representing a signal delay for the signal input of eachamplifier. As described above, the processor(s) 106 can access and/or orreceive speaker data representing information on the speaker(s) 104(e.g., from an internal and/or external data source). Responsive toreceiving the signal 214, the processor(s) 106 can perform thefunction(s) 108, based on the speaker data, and can send signals 218 toeach of the speaker(s) 104. Each of the speaker(s) 104 can emit acousticenergy based on the signals 218, thereby emitting a beam of steeredacoustic energy 216.

The foregoing description of techniques for emitting a beam of acousticenergy 216 are described and shown in the context of a single beam ofacoustic energy. However, in additional or alternative examples, thesame or similar techniques can be implemented to output any number ofbeams of acoustic energy, as described below. In some examples, thesignal 214 can include data to instruct the acoustic array 102A tooutput at least a first beam of acoustic energy and a second beam ofacoustic energy (e.g., at an offset as described below). In otherexamples, multiple signals 214 can be sent to the acoustic array 102A,which can instruct the acoustic array 102A to output multiple beams ofacoustic energy (e.g., a first signal for instructing the acoustic array102A to output the first beam of acoustic energy and a second signal forinstructing the acoustic array 102A to output the second beam ofacoustic energy).

While the acoustic array 102A is illustrated as a linear arrayconfiguration (e.g., configuration associated with a closed-formsolution for delays and/or gains for beam steering), in alternativeexamples, the acoustic array 102A can have another configuration (e.g.,curved, non-uniform, arbitrary, etc.). That is, the illustratedconfiguration of the acoustic array 102A should not be construed as alimitation.

FIGS. 3A and 3B illustrate an example of outputting an acousticnotification to alert a pedestrian of a possible collision. FIG. 3Aillustrates a perspective view of an environment 300 within which avehicle 100 is positioned. FIG. 3B illustrates a top view of theenvironment 300 (with the trajectory lines omitted for clarity).

In at least one example, the sensor system(s) 200 can generate sensordata 202 and provide such sensor data 202 to the vehicle computingdevice(s) 204. The localizer system 206 can analyze the sensor data 202to determine local pose data (e.g., position, orientation estimationdata) for the location of the vehicle 100 in the environment 300. In atleast one example, the planning system 210 can determine a trajectory(T_(v)) of the vehicle 100 as indicated by the arrow. For the purposesof this discussion, a trajectory can be a sequence of positions, poses,velocities, and/or accelerations of the vehicle 100 as it proceedsthrough a limited portion of an environment, such as the environment300. In at least one example, the perception system 208 can process thesensor data 202 to detect a pedestrian 302 in the environment 300. In atleast one example, the planning system 210 can estimate a trajectory(T_(p)) for the pedestrian 302. In at least one example, the planningsystem 210 can determine a location associated with where the pedestriantrajectory (T_(p)) and the vehicle trajectory (T_(v)) are likely tointersect (which, in some examples, may cause a collision between thevehicle 100 and the pedestrian 302 or cause the vehicle 100 to comewithin an unsafe distance of the pedestrian 302). In at least oneexample, the planning system 210 can estimate one or more thresholdlocations in the environment 300, at which to communicate an acousticnotification when the location of the pedestrian 302 coincides with thethreshold locations along the pedestrian trajectory (T_(p)). Thecoincidence of the location of the pedestrian 302 and a thresholdlocation can correspond to a trigger event. That is, in at least oneexample, the one or more threshold locations can trigger the output ofacoustic notifications (e.g., when the location of the pedestrian 302coincides with a threshold location).

The planning system 210 can determine the location of the pedestrian302, which can correspond to Cartesian coordinates (e.g., X, Y, Z),polar coordinates, an angle, etc. In at least one example, the locationof the pedestrian 302 can be relative to a location of the vehicle 100and/or a reference location on the vehicle 100 (e.g., a reference pointon the acoustic array 102A). In at least one example, the planningsystem 210 can compare the location of the pedestrian 302 (along thepedestrian trajectory (T_(p))) with one or more threshold locations and,based at least in part on the planning system 210 determining that thepedestrian trajectory (T_(p)) crosses a threshold location, the planningsystem 210 can send an indication to the audio output determinationsystem 212. Responsive to receiving the indication from the planningsystem 210, the audio output determination system 212 can generate atrigger signal for causing an acoustic notification to be output by oneor more of the acoustic arrays 102.

In at least one example, the audio output determination system 212 canaccess audio signal data (e.g., from an audio signal data storage (e.g.,one or more digital audio files), an external resource (e.g., the Cloud,the Internet, a data repository, etc.), etc.) and select an audio signalthat is to be output as an acoustic notification (e.g., an acousticalert, etc.). That is, the audio output determination system 212 canselect data representing an audio signal that can be used to generatethe acoustic notification using one or more of the acoustic arrays 102.Different audio signals can be representative of different information(e.g., threat levels, etc.). In some examples, an acoustic notificationcan comprise more than one audio signal.

In at least one example, an acoustic notification can be associated witha multi-beam output, wherein a first beam of acoustic energy 304A isoutput at a first time (T₀) and a second beam of acoustic energy 304B isoutput at a second time (T₁). In at least one example, the first time(T₀) and the second time (T₁) can be associated with a period of time(e.g., 100 ms, etc.) such that the first beam 304A and the second beam304B are perceived by the pedestrian 302 sequentially. In at least oneexample, the first beam 304A and the second beam 304B can be emitted indifferent directions of propagation. In such an example, the audiooutput determination system 212 can leverage the location of thepedestrian 302 and the location of the vehicle 100 to calculatedirections of propagation for the beams of steered acoustic energy 304Aand 304B. In some examples, the audio output determination system 212can determine one or more directions of propagation for one or morebeams of steered acoustic energy that are emitted between the first beamof acoustic energy 304A and the second beam of acoustic energy 304B(e.g., either continuously or discretely) so that the acousticnotification is perceived as sweeping from a first position to a secondposition relative to the pedestrian 302. Though described above withrespect to a single period of time (e.g., a delay period between T₀ andT₁), in at least some examples, the beam(s) of steered acoustic energymay oscillate from a first side of the pedestrian 302 to a second sideof the pedestrian 302 with a given frequency (e.g., 10 Hz). In suchexamples, a third beam of steered acoustic energy can be output in thefirst direction of propagation at a third time and a fourth beam ofsteered acoustic energy can be output in the second direction at afourth time to effectuate the oscillation. In some examples, the delayperiod between the second time and third time and the third time and thefourth time can correspond to the delay period between the first timeand the second time. In other examples, the delay periods between thefirst time, second time, third time, and/or fourth time can bedifferent. As would be appreciated, in such an example, the relativedirections of emission of the beams 304A, 304B may change based ondetermined positions of the pedestrian and any motion of the vehicle100.

In at least one example, the audio output determination system 212 candetermine the location of the pedestrian 302 at a point corresponding toa threshold location and the location of the vehicle 100 to calculate acoordinate (e.g., an angle or other direction of emission) for a firstdirection of propagation of the first beam 304A. For instance, the audiooutput determination system 212 can determine the coordinate based on apredetermined reference point on the vehicle 100 and/or on anotherpredetermined reference point on the acoustic array 102A. As oneexample, if a predetermined reference point has coordinates (X_(a),Y_(a)), a processor, circuity, an algorithm or some combination of theforegoing can calculate the coordinate for the first beam 304A (e.g.,based on trigonometric analysis) relative to vehicle trajectory (T_(v)).Furthermore, in at least one example, the audio output determinationsystem 212 can additionally calculate a coordinate (e.g., an angle orother direction of emission) for a second direction of propagation ofthe second beam 304B. As one example, if a predetermined reference pointhas coordinates (X_(a), Y_(a)), a processor, circuity, an algorithm orsome combination of the foregoing can calculate the coordinate for thesecond beam 304B (e.g., based on trigonometric analysis) relative tovehicle trajectory (T_(v)).

In at least one example, the first direction of propagation and thesecond direction of propagation can be offset by an angle. In someexamples, the angle can be determined based on an extent of thepedestrian 302 (or average pedestrian), a pose of the pedestrian 302(e.g., position, orientation, etc.), a distance between the pedestrian302 and the vehicle 100, an angle of the pedestrian 302 relative to thevehicle 100 (e.g., angle from a normal of the vehicle 100), a type ofmessage to be communicated, etc. In at least one example, the angularoffset can cause the first beam 304A to be emitted on a first side ofthe pedestrian 302 and the second beam 304B to be emitted on a second,opposite side of the pedestrian 302, such that the acoustic notificationmoves from a first side to a second side (e.g., “wiggles”). Forinstance, in FIGS. 3A and 3B, the first beam 304A is shown as beingemitted behind the pedestrian 302 and the second beam 304B is shown asbeing emitted in front of the pedestrian 302. However, in additional oralternative examples, the first beam 304A can be emitted to the left ofthe pedestrian 302 and the second beam 304B is shown as being emitted tothe right of the pedestrian 302, or vice versa. In at least one example,the directions of emission of the first and second beams 304A, 304B aredetermined such that the acoustic beams are first incident on a firstear of the pedestrian 302 and subsequently on a second ear of thepedestrian 302. More generally, the emission directions are determinedsuch that width of the beams 304A, 304B can be based on an extent (e.g.,height, length, width) of the pedestrian 302.

As described above with reference to FIG. 2, in at least one example,the audio output determination system 212 can send a signal 214 to oneor more acoustic arrays 102. In at least one example, the signal 214 canbe associated with a trigger signal and can include data such as anaudio signal selected, directions (e.g., the first direction and thesecond direction) of propagation for emitting the beams (e.g., the firstbeam 304A and the second beam 304B) of acoustic steered energy, and/or atiming for emitting the beams of acoustic steered energy (e.g., theamount of time between the first time (T₀) and the second time (T₁)).That is, the audio output determination system 212 can send the signal214 to the acoustic array 102A to cause the speaker(s) 104 to emit thefirst beam 304A and the second beam 304B in their respective directionsof propagation and at their respective times. In at least one example,the first beam 304A and the second beam 304B, when emitted, can beperceived by the pedestrian 302 as moving side to side (e.g., wiggling).As a result, the pedestrian 302, using stereoscopic hearing, canlocalize the vehicle 100 based on the acoustic notification, and in someexamples, can determine the behavior of the vehicle 100 (e.g., adirection the vehicle 100 is moving, etc.).

In at least one example, upon receiving the signal 214, the acousticarray 102A can emit the beams of steered acoustic energy 304 towards thepedestrian 302 along the directions of propagation, and at theprescribed times (and/or constantly). The acoustic array 102A can emitthe beams of steered acoustic energy 304 based at least in part on thesignal 214 and/or speaker data, as described above. For instance, in atleast one example, the processor(s) 106 associated with the acousticarray 102 can leverage the signal 214 and/or the speaker data tocalculate data representing a gain for the gain input of each amplifiercoupled to a speaker and a signal delay for the signal input of eachamplifier to effectuate the acoustic notification. Furthermore, in someexamples, the acoustic array 102A can utilize additional or alternativesignal(s), such as object pose, microphone signal(s), environmentalsignal(s), audio signals, etc. for determining how to emit the beams ofsteered acoustic energy 304 for effectuating the acoustic notification.

In at least one example, the acoustic array 102A can emit the first beam304A indicative of the data representing the selected audio signal(e.g., the acoustic energy reproduces the sound encoded in the audiosignal), along the first direction of propagation at the first time(T₀), and can emit the second beam 304B indicative of the datarepresenting the selected audio signal, along the second direction ofpropagation at the second time (T₁). That is, at least a portion of thespeaker(s) 104 can emit the first beam 304A indicative of the datarepresenting the selected audio signal (e.g., the acoustic energyreproduces the sound encoded in the audio signal), along the firstdirection of propagation at the first time (T₀), and at least a portionof the speaker(s) 104 can emit the second beam 304B indicative of thedata representing the selected audio signal, along the second directionof propagation at the second time (T₁). In some examples, the portionsof speaker(s) 104 can be the same speakers in the acoustic array 102Aand, in other examples, the portions of speaker(s) 104 can be differentspeakers in the acoustic array 102A.

In some examples, the audio output determination system 212 can send oneor more subsequent signals 214 to the acoustic array 102A to cause thespeaker(s) 104 to oscillate between emitting the first beam 304A and thesecond beam 304B in their respective directions of propagation at adefined frequency (e.g., 10 Hz or 100 ms) such that the acousticnotification is perceived by the pedestrian 302 as moving side to side(e.g., wiggling) for a sustained amount of time. In such examples, theaudio output determination system 212 can determine a frequency forsending the subsequent signals 214, which corresponds to a rate at whichthe first beam 304A and the second beam 304B are subsequently emittedfrom the one or more acoustic arrays 102. That is, in at least oneexample, the audio output determination system 212 can determine afrequency at which the pedestrian 302 hears the acoustic notificationmove from side to side repeatedly. In at least one example, thesubsequent signals 214 can include updated directions of propagation andor timing, which can be based on updated sensor data 202 received by thevehicle computing device(s) 204. That is, as the vehicle 100 and/or thepedestrian 302 move, the audio output determination system 212 canupdate the directions of propagation and/or timing at which additionalbeams of acoustic energy are to be output by the acoustic array 102A.

In some examples, the sound of the acoustic notification can vary, forinstance, based on a proximity of a pedestrian 302 relative to thevehicle 100 (e.g., level of threat). In such examples, subsequentsignals 214 can include different audio signals. Additional detailsassociated with varying the sound of the acoustic notification (e.g.,the audio signal) are described in U.S. Pat. No. 9,878,664, entitled“Method for Robotic Vehicle Communication with an External Environmentvia Acoustic Beam Forming,” the entire contents of which are herebyincorporated by reference.

As a result of the acoustic notification emitted by the acoustic array102A, the pedestrian 302 can use stereoscopic hearing to localize thevehicle 100, and in some examples, can determine the behavior of thevehicle 100 (e.g., a direction the vehicle 100 is moving, etc.).

In at least one example, after the acoustic array 102A outputs the beamsof acoustic energy, the localization system 206 and/or perception system208 can determine updated pose information for the vehicle 100 and/orthe pedestrian 302. In at least one example, the planning system 210 canleverage updated pose information to generate an updated trajectory forthe vehicle 100 (e.g., a trajectory that causes the vehicle 100 to avoidthe pedestrian 302 or otherwise change its current trajectory (T_(v)))to mitigate danger or otherwise redirect the vehicle 100.

While the aforementioned examples are directed to providing acousticnotifications to a pedestrian, the same or similar techniques can beinstituted for any other external objects detected in the environment300 of the vehicle 100 (e.g., animals, such as dogs, other vehicles,etc.). Furthermore, while the aforementioned examples are directed toproviding acoustic notifications via the acoustic array 102A, the sameor similar techniques can be instituted for any other acoustic array102B-102N of the vehicle 100.

FIG. 4 illustrates an example of using an acoustic array, such as theacoustic array 102A, for emitting sounds via multiple channels. Thevehicle components shown in FIG. 4 can correspond to the same vehiclecomponents illustrated in FIG. 2. That is, as described above withreference to FIG. 2, the vehicle 100 can include one or more sensorsystem(s) 200 that can be disposed on the vehicle 100. The one or moresensor system(s) 200 can generate sensor data 202, which can be utilizedby vehicle computing device(s) 204 onboard the vehicle 100. In at leastone example, the vehicle computing device(s) 204 can include systems,such as a localization system 206, a perception system 208, a planningsystem 210, and an audio output determination system 212, as describedabove. In at least one example, the audio output determination system212 can send signals 400A-400N (referred to generally as signals 400) tothe acoustic array 102A. For the purpose of this discussion, signals 400can be control signals (e.g., like signal 214).

In at least one example, the acoustic array 102A can have multi-channelfunctionality. That is, one or more of the speaker(s) 104 can beassociated with different channels. For instance, as illustrated, afirst group of speaker(s) 402A can correspond to a first channel, asecond group of speaker(s) 402B can correspond to a second channel, andso on. For the purpose of this discussion, a “group” of speaker(s) cancomprise one or more speakers. The acoustic array 102A can comprise anynumber of channels. Further, though the groups are depicted in FIG. 4 asbeing contiguous for illustrative purposes, in at least some examples,speakers of the groups need not be so limiting (e.g. speakers in a groupmay be separated by one or more speakers from another group).

As described above in FIG. 2, in at least one example, the audio outputdetermination system 212 can be configured to determine when to send asignal 214 to the one or more acoustic arrays 102. That is, the audiooutput determination system 212 can send a single input signal 214,which can be output by different speaker(s) 104 in different ways. InFIG. 4, however, the audio output determination system 212 can beconfigured to determine when to send signals 400 to individual channelsof the one or more acoustic arrays 102. That is, in FIG. 4, the audiooutput determination system 212 can send multiple signals 400 that canbe output by different channels(s) of speakers in different ways.

In at least one example, the audio output determination system 212 cansend a first signal 400A to a first group of speaker(s) 402A, a secondsignal 400B to the second group of speaker(s) 402B, and so on. Eachsignal 400A-400N can include data indicating an audio signal, a timingfor emitting a sound, a volume for emitting a sound, audiocharacteristics (e.g., a frequency, a volume, a pitch, a tone, aduration, etc.) for emitting a sound, etc. In at least one example,individual signals (e.g., signal 400A, signal 400B, etc.) can beassociated with a same audio signal or different audio signals, whichcan be associated with a same digital audio file. That is, in at leastone example, each signal 400A-400N can be associated with sound that,when collectively emitted, comprises an acoustic notificationcorresponding to a digital audio file. Furthermore, in at least oneexample, the audio output determination system 212 can determine atiming for emitting a sound, a volume for emitting a sound, audiocharacteristics (e.g., a frequency, a volume, a pitch, a tone, aduration, etc.) for emitting a sound, etc. via a particular channel andcan send such information to a group of speaker(s) associated with theparticular channel. Responsive to receiving the signals 400, each groupof speakers 402A-402N can emit a sound. In at least one example,responsive to receiving a signal 400A, the first group of speaker(s)402A can emit a sound 404A, responsive to receiving a signal 400B, thesecond group of speaker(s) 402B can emit a sound 404B, and so on.

Each group of speakers corresponding to a channel in the multi-channelconfiguration can emit a sound based on the respective signal received,and as such, a plurality of sounds can be spatialized across the surfaceof the vehicle 100. That is, the multi-channel configuration can beutilized to dynamically output sounds via individual channels such thatthe plurality of sounds can be spatialized across the surface of thevehicle 100. For the purpose of this discussion, the multi-channelconfiguration can be used to modify at least one of a timing foremitting a sound, a volume for emitting a sound, an audio characteristicfor emitting a sound, etc. to cause the sounds to be output dynamically.Additional details are described below with reference to FIGS. 5A-5D. Insome examples, where a channel is associated with more than one speaker,the channel can receive a signal indicating a direction of propagationand the multiple speakers can output a beam of steered energy as asound.

In some examples, the audio output determination system 212 can send oneor more subsequent signals to the acoustic array 102A to cause thespeaker(s) 104 to emit additional sounds continuously such that theacoustic notification is output for a sustained amount of time. In suchexamples, the audio output determination system 212 can determine afrequency for sending the subsequent signals, which corresponds to arate at which the additional sounds are subsequently emitted from theacoustic array 102A. In an alternate example, the signals 400 caninclude instructions to emit the additional sounds such that theacoustic notification is output for a sustained amount of time (e.g.,which can correspond to a predetermined period of time or the receipt ofa stop signal).

In some examples, the audio output determination system 212 can sendsignals 400 to the acoustic array 102A responsive to a trigger event(e.g., velocity falls below a threshold velocity, object detection,location, etc.). In such examples, a default state of the vehicle 100may be to not send signals 400 (e.g., and therefore not emit acousticnotifications). In an alternative example, the audio outputdetermination system 212 can send signals 400 to the acoustic array 102Acontinuously, in near-real time, so long as the vehicle 100 is turned on(e.g., running). That is, in some examples, a default state of thevehicle 100 may be to send signals 400 (e.g., and therefore emitacoustic notifications). In such examples, the trigger event cancorrespond to the vehicle 100 being turned on. In such examples, theaudio output determination system 212 can determine not to send signals400 responsive to a stop event (e.g., velocity exceeds a thresholdvelocity, no object detection, presence in a particular location, etc.).

In at least one example, the audio output determination system 212 cansend signals 400 to the acoustic array 102A responsive to determiningthat the vehicle 100 is travelling at a velocity below a thresholdvelocity. For instance, the audio output determination system 212 cancause sounds to be emitted by the speaker(s) 104 when the vehicle 100 istravelling at a velocity below a threshold velocity (e.g., in the city).In some examples, the audio output determination system 212 can sendsignals 400 continuously until the velocity of the vehicle 100 isdetermined to meet or exceed the threshold velocity. That is, the audiooutput determination system 212 can cause sounds to not be emitted bythe speaker(s) 104 when the vehicle 100 is travelling at a velocity ator above a threshold velocity (e.g., on the highway).

In another example, the audio output determination system 212 can sendsignals 400 to the acoustic array 102A responsive to detecting an objectwithin a threshold distance of the vehicle 100. For instance, the audiooutput determination system 212 can cause sounds to be emitted by thespeaker(s) 104 when the vehicle 100 is proximate to an object (e.g.,within a threshold distance of the object). In some examples, the audiooutput determination system 212 can send signals 400 continuously untilthe vehicle (e.g., the perception system 208) no longer detects anobject within a threshold distance of the vehicle 100. That is, theaudio output determination system 212 can cause sounds to not be emittedby the speaker(s) 104 when the vehicle 100 is travelling in anenvironment where other objects are not detected.

In yet another example, the audio output determination system 212 cansend signals 400 to the acoustic array 102A responsive to a location ofthe vehicle 100. For instance, the audio output determination system 212can cause sounds to be emitted by the speaker(s) 104 when the vehicle100 is in a particular location (or a particular geofence) (e.g., acity, a neighborhood, etc.) as determined by location data (e.g., GPSdata), map data, etc. (e.g., as determined by the localization system206). In some examples, the audio output determination system 212 cansend signals 400 continuously until the vehicle 100 (e.g., as determinedby the perception system 208) is no longer in the particular location.Conversely, in some examples, the audio output determination system 212can cause sounds to not be emitted by the speaker(s) 104 when thevehicle 100 is in a particular location (e.g., a city, a neighborhood,etc.) as determined by location data (e.g., GPS data), map data, etc.(e.g., as determined by the localization system 206).

Further, in at least one example, the audio output determination system212 can cause sounds to be emitted for a predetermined period of timeafter which the audio output determination system 212 can cause soundsnot to be emitted. In at least one example, the predetermined period oftime can be informed by the digital audio file to which the acousticnotification corresponds.

While the acoustic array 102A is illustrated as a linear arrayconfiguration (e.g., a closed-form solution), in alternative examples,the acoustic array 102A can have another configuration (e.g., arbitraryarray, etc.). That is, the illustrated configuration of the acousticarray 102A should not be construed as a limitation.

FIGS. 5A-5D illustrate examples of acoustic notifications that can beoutput via the acoustic array 102A using a multi-channel configuration.In at least one example, the individual channels can output sounds 500at different times, at different volumes, with different audiocharacteristics, etc. to cause the sounds 500 to be output dynamically.In some examples, the sounds 500 output via each channel can beassociated with the same audio signal or different audio signals. InFIGS. 5A-5D each speaker corresponds to a different channel.

As illustrated in FIG. 5A, the sounds 500 are output by differentchannels, at different times, and/or at different volumes (e.g., asrepresented by the length of representative line) such that a pedestriancan perceive the acoustic notification as agitating (e.g., “fluttering”)across the surface of the vehicle 100. As such, the pedestrian canlocalize the vehicle 100, determine a geometry of the vehicle 100 (e.g.,width, length, etc.), and, in some examples, determine a behavior of thevehicle 100 (e.g., slowing down, speeding up, turning, etc.). In atleast one example, the sounds 500 can be output one after another,moving in a direction across a surface of the vehicle 100 (e.g., rightto left, left to right, front to back, back to front, etc.). The delaybetween each emission of a sound can be due to timing as indicated inthe signal sent to each group of speaker(s) corresponding to eachchannel (e.g., from the audio output determination system 212) (e.g., insignals 400).

As illustrated in FIG. 5B, sounds 500 are output by different channels,at a same time, such that a pedestrian can perceive the audio signal aslinearly progressing across the surface of the vehicle 100. As such, thepedestrian can localize the vehicle 100, determine a size of the vehicle100 (e.g., width, length, etc.), and, in some examples, determine abehavior of the vehicle 100 (as described above above). In at least oneexample, an acoustic notification can be played sequentially through allchannels starting at one side of the vehicle and progressing to theopposite side, as illustrated in FIG. 5C. That is, the sounds 500 can beoutput one after another, moving in a direction across a surface of thevehicle 100 (e.g., right to left, left to right, front to back, back tofront, etc.). The delay between each sound can be due to timing asindicated in the signal sent to each group of speaker(s) correspondingto each channel (e.g., from the audio output determination system 212).In some examples, each sound can be emitted for a particular period oftime such that the audio signal can be perceived by a pedestrian aspulsating across the surface of the vehicle 100. In another example, anacoustic notification can include a plurality of sounds, having a samevolume, that can be emitted at random times, as illustrated in FIG. 5D.That is, the sounds 500 can be output in a random order across a surfaceof the vehicle 100 (e.g., right to left, left to right, front to back,back to front, etc.).

In any of the examples illustrated and described in FIGS. 5A-5D, one ormore audio characteristics can be varied with respect to each soundemitted from each channel.

FIG. 6 illustrates an example of outputting an acoustic notification toalert a pedestrian of a presence of a vehicle 100. FIG. 6 illustrates atop view of an environment 600 within which the vehicle 100 ispositioned. As illustrated, a pedestrian 602 is in the environment 600.

As described above, in at least one example, the audio outputdetermination system 212 can send a first signal 400A to a first groupof speaker(s) 402A, a second signal 400B to the second group ofspeaker(s) 402B, and so on. Responsive to receiving the signals 400,each group of speakers can emit a sound. In at least one example, theaudio output determination system 212 can determine a timing foremitting the sound, a volume for emitting the sound, audiocharacteristics associated with emitting the sound, etc. via aparticular channel, and can send such information to a group ofspeaker(s) associated with the particular channel. Each group ofspeakers corresponding to a channel in the multi-channel configurationcan emit a sound based on the signal received, and as such, a pluralityof sounds 604 can be spatialized across the surface of the vehicle 100,as illustrated in FIG. 6. That is, as illustrated in FIG. 6, themulti-channel configuration can be utilized to dynamically output soundsvia individual channels such that the plurality of sounds can bespatialized across the surface of the vehicle 100 (e.g., as an acousticnotification to notify the pedestrian 602).

In some examples, the audio output determination system 212 can sendsignals 400 to the acoustic array 102A continuously, in near-real time,so long as the vehicle 100 is turned on (e.g., running). In suchexamples, the audio output determination system 212 can determine not tosend signals 400 responsive to a stop event (e.g., velocity exceeds athreshold velocity, no object detection, presence in a particularlocation, etc.). In alternative examples, the audio output determinationsystem 212 can send signals 400 to the acoustic array 102A responsive toa trigger event (e.g., velocity falls below a threshold velocity, objectdetection, location, etc.). In such examples, the default state may beto not send signals 400.

While the aforementioned examples are directed to providing acousticnotifications to a pedestrian, the same or similar techniques can beinstituted for any other external objects detected in the environment600 of the vehicle 100. Furthermore, while the aforementioned examplesare directed to providing acoustic notifications via the acoustic array102A, the same or similar techniques can be instituted for any otheracoustic array 102B-102N of the vehicle 100.

FIG. 7 illustrates a block diagram of an example system 700 forfacilitating acoustic notifications. In at least one example, the system700 can include the vehicle 100, as described above with reference toFIGS. 1-6.

Further, as described above, the vehicle 100 can include, one or moresensor systems 200, one or more emitters 702, one or more communicationconnections 704, at least one direct connection 706, and one or moredrive modules 708.

The vehicle computing device(s) 204 can include one or more processors710 and memory 712 communicatively coupled with the one or moreprocessors 710. In the illustrated example, the vehicle 100 is anautonomous vehicle; however, the vehicle 100 could be any other type ofvehicle, as described above. In the illustrated example, the memory 712of the vehicle computing device(s) 204 stores the localization system206, the perception system 208, the planning system 210, and the audiooutput determination system 212, as described above with reference toFIG. 2. In at least one example, the audio output determination system212 can store an audio signal data storage 714, which can store one ormore digital audio files corresponding to acoustic notifications. Eachdigital audio file can comprise one or more audio signals that, whenemitted by speaker(s) 104 of an acoustic array 102A, can correspond toan acoustic notification. In some examples, the audio signal datastorage 714 can be stored in association with another vehicle systemand/or remotely. Furthermore, in some examples, audio signals can bestored and/or accessible via an external resource (e.g., the Cloud, theInternet, a data repository, etc.).

In at least one example, the vehicle computing device(s) 204 can includeone or more system controllers 716, which can be configured to controlsteering, propulsion, braking, safety, emitters, communication, andother systems of the vehicle 100. These system controller(s) 716 cancommunicate with and/or control corresponding systems of the drivemodule(s) 708 and/or other components of the vehicle 100. In at leastone example, the system controller(s) 716 can receive instructions fromone or more other systems of the vehicle 100 (e.g., the planning system210).

In at least one example, the sensor system(s) 200 can include LIDARsensors, RADAR sensors, ultrasonic transducers, SONAR sensors, locationsensors (e.g., GPS, compass, etc.), inertial sensors (e.g., inertialmeasurement units, accelerometers, magnetometers, gyroscopes, etc.),cameras (e.g., RGB, IR, intensity, depth, etc.), microphones, wheelencoders, environment sensors (e.g., temperature sensors, humiditysensors, light sensors, pressure sensors, etc.), etc. The sensorsystem(s) 200 can include multiple instances of each of these or othertypes of sensors. For instance, the LIDAR sensors can include individualLIDAR sensors located at the corners, front, back, sides, and/or top ofthe vehicle 100. As another example, the camera sensors can includemultiple cameras disposed at various locations about the exterior and/orinterior of the vehicle 100. The sensor system(s) 200 can provide inputto the vehicle computing device(s) 204. Additionally and/oralternatively, the sensor system(s) 200 can send sensor data, via theone or more networks, to one or more computing device(s) at a particularfrequency, after a lapse of a predetermined period of time, in nearreal-time, etc.

The vehicle 100 can also include one or more emitters 702 for emittinglight and/or sound, as described above. The emitters 702 in this exampleinclude interior audio and visual emitters to communicate withpassengers of the vehicle 100. By way of example and not limitation,interior emitters can include speakers, lights, signs, display screens,touch screens, haptic emitters (e.g., vibration and/or force feedback),mechanical actuators (e.g., seatbelt tensioners, seat positioners,headrest positioners, etc.), and the like. The emitters 702 in thisexample also include exterior emitters. By way of example and notlimitation, the exterior emitters in this example include light emitters(e.g., indicator lights, signs, light arrays, projectors, etc.) tovisually communicate with pedestrians, other drivers, other nearbyvehicles, etc., one or more audio emitters (e.g., speakers, speakerarrays, horns, etc.) to audibly communicate with pedestrians, otherdrivers, other nearby vehicles, etc., etc. In at least one example, theemitter(s) 702 can include one or more acoustic arrays 102, as describedabove. The emitters can be disposed at various locations about theexterior and/or interior of the vehicle 100.

The vehicle 100 can also include one or more communication connection(s)704 that enable communication between the vehicle 100 and one or moreother local or remote computing device(s). For instance, thecommunication connection(s) 704 can facilitate communication with otherlocal computing device(s) on the vehicle 100 and/or the drive module(s)708. Also, the communication connection(s) 704 can allow the vehicle tocommunicate with other nearby computing device(s) (e.g., other nearbyvehicles, traffic signals, etc.). The communications connection(s) 704also enable the vehicle 100 to communicate with a remote teleoperationscomputing device or other remote services.

The communications connection(s) 704 can include physical and/or logicalinterfaces for connecting the vehicle computing device(s) 204 to anothercomputing device or a network. For example, the communicationsconnection(s) 704 can enable Wi-Fi-based communication such as viafrequencies defined by the IEEE 802.11 standards, short range wirelessfrequencies such as BLUETOOTH®, or any suitable wired or wirelesscommunications protocol that enables the respective computing device tointerface with the other computing device(s).

In at least one example, the vehicle 100 can include one or more drivemodules 708. In some examples, the vehicle 100 can have a single drivemodule 708. In at least one example, if the vehicle 100 has multipledrive modules 708, individual drive modules 708 can be positioned onopposite ends of the vehicle 100 (e.g., the front and the rear, etc.).In at least one example, the drive module(s) 708 can include one or moresensor systems to detect conditions of the drive module(s) 708 and/orthe surroundings of the vehicle 100. By way of example and notlimitation, the sensor system(s) can include one or more wheel encoders(e.g., rotary encoders) to sense rotation of the wheels of the drivemodule, inertial sensors (e.g., inertial measurement units,accelerometers, gyroscopes, magnetometers, etc.) to measure orientationand acceleration of the drive module, cameras or other image sensors,ultrasonic sensors to acoustically detect objects in the surroundings ofthe drive module, LIDAR sensors, RADAR sensors, etc. Some sensors, suchas the wheel encoders can be unique to the drive module(s) 708. In somecases, the sensor system(s) on the drive module(s) 708 can overlap orsupplement corresponding systems of the vehicle 100 (e.g., sensorsystem(s) 200).

The drive module(s) 708 can include many of the vehicle systems,including a high voltage battery, a motor to propel the vehicle 100, aninverter to convert direct current from the battery into alternatingcurrent for use by other vehicle systems, a steering system including asteering motor and steering rack (which can be electric), a brakingsystem including hydraulic or electric actuators, a suspension systemincluding hydraulic and/or pneumatic components, a stability controlsystem for distributing brake forces to mitigate loss of traction andmaintain control, an HVAC system, lighting (e.g., lighting such ashead/tail lights to illuminate an exterior surrounding of the vehicle),and one or more other systems (e.g., cooling system, safety systems,onboard charging system, other electrical components such as a DC/DCconverter, a high voltage junction, a high voltage cable, chargingsystem, charge port, etc.). Additionally, the drive module(s) 708 caninclude a drive module controller which can receive and preprocess datafrom the sensor system(s) and to control operation of the variousvehicle systems. In some examples, the drive module controller caninclude one or more processors and memory communicatively coupled withthe one or more processors. The memory can store one or more modules toperform various functionalities of the drive module(s) 708. Furthermore,the drive module(s) 708 also include one or more communicationconnection(s) that enable communication by the respective drive modulewith one or more other local or remote computing device(s).

The processor(s) 710 of the vehicle 100 can be any suitable processorcapable of executing instructions to process data and perform operationsas described herein. By way of example and not limitation, theprocessor(s) 710 can comprise one or more Central Processing Units(CPUs), Graphics Processing Units (GPUs), or any other device or portionof a device that processes electronic data to transform that electronicdata into other electronic data that can be stored in registers and/ormemory. In some examples, integrated circuits (e.g., ASICs, etc.), gatearrays (e.g., FPGAs, etc.), and other hardware devices can also beconsidered processors in so far as they are configured to implementencoded instructions.

The memory 712 of the vehicle 100 is an example of non-transitorycomputer-readable media. The memory 712 can store an operating systemand one or more software applications, instructions, programs, and/ordata to implement the methods described herein and the functionsattributed to the various systems. In various implementations, thememory can be implemented using any suitable memory technology, such asstatic random access memory (SRAM), synchronous dynamic RAM (SDRAM),nonvolatile/Flash-type memory, or any other type of memory capable ofstoring information. The architectures, systems, and individual elementsdescribed herein can include many other logical, programmatic, andphysical components, of which those shown in the accompanying figuresare merely examples that are related to the discussion herein.

It should be noted that, in alternative examples, components of thevehicle 100 can be associated with the remote computing device(s) and/orcomponents of the remote computing device(s) can be associated with thevehicle 100. That is, the vehicle 100 can perform one or more otherfunctions associated with remote computing device(s), and vice versa.Furthermore, in some examples, one or more functions performed by thevehicle computing device(s) 204 can be performed by one or morecomponents of the acoustic arrays 102, and vice versa.

FIGS. 8-10 are flowcharts showing example methods for using acousticnotifications for pedestrian notification as described herein. Themethods illustrated in FIGS. 8-10 are described with reference to thevehicle 100 shown in FIGS. 1-7 for convenience and ease ofunderstanding. However, the methods illustrated in FIGS. 8-10 are notlimited to being performed using vehicle 100, and can be implementedusing any of the other vehicles described in this application, as wellas vehicles other than those described herein. Moreover, the vehicle 100described herein is not limited to performing the methods illustrated inFIGS. 8-10.

The methods 800-1000 are illustrated as collections of blocks in logicalflow graphs, which represent sequences of operations that can beimplemented in hardware, software, or a combination thereof. In thecontext of software, the blocks represent computer-executableinstructions stored on one or more computer-readable storage media that,when executed by one or more processors, perform the recited operations.Generally, computer-executable instructions include routines, programs,objects, components, data structures, and the like that performparticular functions or implement particular abstract data types. Theorder in which the operations are described is not intended to beconstrued as a limitation, and any number of the described blocks can becombined in any order and/or in parallel to implement the processes. Insome embodiments, one or more blocks of the process can be omittedentirely. Moreover, the methods 800-1000 can be combined in whole or inpart with each other or with other methods.

FIG. 8 illustrates a flow diagram illustrating an example process 800for causing beams of acoustic energy to be emitted by speakers of anacoustic array.

Block 802 illustrates receiving sensor data from the one or more sensorsystems of a vehicle. As described above, in at least one example, thevehicle 100 can be associated with one or more sensor system(s) 200 thatcan be disposed on the vehicle 100. The one or more sensor system(s) 200can include LIDAR sensors, RADAR sensors, ultrasonic transducers, SONARsensors, location sensors (e.g., GPS, compass, etc.), inertial sensors(e.g., inertial measurement units, accelerometers, magnetometers,gyroscopes, etc.), cameras (e.g., RGB, IR, intensity, depth, etc.),wheel encoders, microphones, environmental sensors (e.g., temperaturesensors, humidity sensors, light sensors, pressure sensors, etc.), etc.The one or more sensor system(s) 200 can generate sensor data 202, whichcan be utilized by the localization system 206, perception system 208,and/or planning system 210.

Block 804 illustrates determining whether a trigger event occurs. Asdescribed above, in at least one example, the audio output determinationsystem 212 can utilize the sensor data and/or one or more outputs of thelocalization system 206, the perception system 208, and/or the planningsystem to determine when to send a signal (e.g., a control signal) toone or more acoustic arrays 102. In at least one example, the audiooutput determination system 212 can determine to send the signalresponsive to determining an occurrence of a trigger event.

In some examples, a trigger event can correspond to an identification ofa pedestrian (or other object) proximate the vehicle 100 (e.g., asdetermined by the perception system 208). In an additional oralternative example, a trigger event can correspond to a coincidence ofa location of a pedestrian with one or more threshold locations in anenvironment (that is indicative of a potential collision or thepedestrian and the vehicle 100 coming within an unsafe distance of oneanother). In at least one example, the sensor system(s) 200 can generatesensor data 202 and provide such sensor data 202 to the vehiclecomputing device(s) 204. The localizer system 206 can analyze the sensordata 202 to determine local pose data (e.g., position, orientationestimation data) for the location of the vehicle 100 in the environment.In at least one example, the planning system 210 can determine atrajectory (T_(v)) of the vehicle 100. For instance, with reference toFIG. 3, the perception system 208 can process the sensor data 202 todetect a pedestrian 302 in the environment 300. In at least one example,the planning system 210 can estimate a trajectory (T_(p)) for thepedestrian 302. In at least one example, the planning system 210 candetermine a location associated with where the pedestrian trajectory(T_(p)) and the vehicle trajectory (T_(v)) are likely to intersect(which, in some examples, may cause a collision between the vehicle 100and the pedestrian 302 or cause the vehicle 100 to come within an unsafedistance of the pedestrian 302). In at least one example, the planningsystem 210 can estimate one or more threshold locations in theenvironment 300, at which to communicate an acoustic notification whenthe location of the pedestrian 302 coincides with the thresholdlocations along the pedestrian trajectory (T_(p)). The coincidence ofthe location of the pedestrian 302 and a threshold location cancorrespond to a trigger event.

Additionally or alternatively, in some examples, a trigger event cancorrespond to a velocity of the vehicle 100 being below a threshold. Forinstance, in at least one example, the sensor system(s) 200 can generatesensor data 202 and provide such sensor data 202 to the vehiclecomputing device(s) 204. The localizer system 206 can analyze the sensordata 202 to determine local pose data (e.g., position, orientationestimation data) for the location of the vehicle 100 in the environment.The planning system 210 can analyze the sensor data 202 and/or dataoutput from the localizer system 206 to determine a velocity of thevehicle 100. The audio output determination system 212 can compare thevelocity of the vehicle 100 with a threshold velocity. Based at least inpart on the audio output determination system 212 determining that thevelocity is below a threshold velocity, the audio output determinationsystem 212 can determine an occurrence of a trigger event.

In at least one example, a trigger event can correspond to a detectionof an object within a threshold distance of the vehicle 100. Forinstance, in at least one example, the sensor system(s) 200 can generatesensor data 202 and provide such sensor data 202 to the vehiclecomputing device(s) 204. The localizer system 206 can analyze the sensordata 202 to determine local pose data (e.g., position, orientationestimation data) for the location of the vehicle 100 in the environment.In at least one example, the perception system 208 can process thesensor data 202 to detect one or more objects in the environment. Theplanning system 210 can determine a distance between the vehicle 100 andthe one or more objects. In at least one example, the audio outputdetermination system 212 can compare the distance between the vehicleand the one or more objects with a threshold distance, and based atleast in part on determining that the distance is below the thresholddistance, can determine an occurrence of a trigger event.

Further, in at least one example, a trigger event can correspond to alocation of the vehicle 100. For instance, in at least one example, thesensor system(s) 200 can generate sensor data 202 and provide suchsensor data 202 to the vehicle computing device(s) 204. In at least oneexample, the localizer system 206 can determine where the vehicle 100 isin relation to a local and/or global map based at least in part onsensor data 202 received from the sensor system(s) 200 and/or map dataassociated with a map. In some examples, the audio output determinationsystem 212 can utilize a location of the vehicle 100 to determine anoccurrence of a trigger event. For instance, if the location of thevehicle 100 corresponds to a particular location (or a particulargeofence), the audio output determination system 212 can determine anoccurrence of a trigger event.

Additional or alternative trigger events are contemplated herein. Forinstance, in at least one example, actuation of the vehicle 100 (e.g.,turning the vehicle 100 on) can correspond to an occurrence of a triggerevent.

Block 806 illustrates selecting audio signal(s). In at least oneexample, the audio output determination system 212 can access audiosignal data (e.g., from an audio signal data storage (e.g., one or moredigital audio files), an external resource (e.g., the Cloud, theInternet, a data repository, etc.), etc.) and select an audio signalthat is to be output as an acoustic notification. That is, the audiooutput determination system 212 can select data representing an audiosignal that can be used to generate the acoustic notification using oneor more of the acoustic arrays 102. Different audio signals can berepresentative of different information (e.g., threat levels, etc.). Insome examples, an acoustic notification can be associated with multipleaudio signals.

Block 808 illustrates determining whether an acoustic notification is abeam-formed output or a multi-channel output. In at least one example,the audio output determination system 212 can output different types ofcontrol signals depending on whether an acoustic notification isassociated with a beam-formed output or a multi-channel output. Forinstance, as described above in FIG. 2, in at least one example, theaudio output determination system 212 can be configured to determinewhen to send a single signal (e.g., signal 214) to the one or moreacoustic arrays 102. That is, the audio output determination system 212can send a single control signal, which can be output by differentspeaker(s) 104 in different ways. In FIG. 4, however, the audio outputdetermination system 212 can be configured to determine when to sendmultiple signals (e.g., signals 400) to individual channels of the oneor more acoustic arrays 102. That is, in FIG. 4, the audio outputdetermination system 212 can send multiple signals 400 that can beoutput by different channels(s) of speakers in different ways. In atleast one example, the digital audio file associated with the selectedaudio signal(s) can indicate whether an output is a beam-formed outputor a multi-channel output.

Block 810 illustrates determining directions of propagation for emittingbeam(s) of steered acoustic energy. In at least one example, forinstance, if the acoustic notification is associated with a beamsteering output, the audio output determination system 212 can determineone or more directions of propagation for one or more outputs associatedwith the acoustic notification. In at least one example, the audiooutput determination system 212 can determine a target location (e.g.,corresponding to a location of a target object) for outputting a beam ofacoustic energy and can calculate a coordinate (e.g., an angle or otherdirection of emission) for a direction of propagation of a beam ofacoustic energy. For instance, the audio output determination system 212can determine the coordinate based on a predetermined reference point onthe vehicle 100 and/or on another predetermined reference point on theacoustic array 102A. As one example, if a predetermined reference pointhas coordinates (X_(a), Y_(a)), a processor, circuity, an algorithm orsome combination of the foregoing can calculate the coordinate for thebeam of acoustic energy (e.g., based on trigonometric analysis) relativeto a vehicle trajectory.

In some examples, one or more beams of acoustic energy can be output inone or more directions. In such examples, the audio output determinationsystem 212 can determine one or more directions of propagation. That is,in such examples, each beam of acoustic energy can have a differentcoordinate (e.g., an angle or other direction of emission) relative tothe vehicle trajectory. In some examples, the offset between directionsof propagation can be determined based on an extent of a target object(e.g., height, length, width, etc.), a pose of a target object (e.g.,position, orientation, etc.), a distance between the target object andthe vehicle 100, an angle of the target object relative to the vehicle100 (e.g., angle from a normal of the vehicle 100), a type of message tobe communicated, etc. In some examples, the one or more directions ofpropagation can be agnostic to a target location and instead can beindicated by a digital audio file associated with an acousticnotification.

In some examples, the audio output determination system 212 candetermine a timing associated with outputting one or more beams ofacoustic energy associated with an audio notification.

Block 812 illustrates sending signal(s) to an acoustic array. In atleast one example, such as when an acoustic notification is associatedwith a beam-formed output, the audio output determination system 212 canbe configured to send signal(s) to an acoustic array 102A-102N. In atleast one example, the signal(s) can be control signal(s) associatedwith a trigger signal and can include data such as an audio signalselected, direction(s) of propagation for emitting one or more beams ofacoustic steered energy, and/or a timing for emitting the one or morebeams of acoustic steered energy. In at least one example, the signal(s)can further include modulation signal data received by acoustic arrays102.

In at least one example, the audio output determination system 212 cansend the signal(s) to an acoustic array, such as acoustic array 102A, toactivate the acoustic array 102A. In at least one example, the audiooutput determination system 212 can send the signal(s) to the acousticarray that is positioned approximately in the direction of the targetobject (e.g., if the target object is in front of the vehicle 100, theaudio output determination system 212 can send the signal(s) to theacoustic array 102A). As described above, in at least one example, theacoustic array 102A can include one or more processors 106 (e.g.,microprocessor(s), digital signal processor(s) (DSP), etc.) that can beconfigured to receive the signal and process the signal to generate,using the acoustic array 102A, a beam of steered acoustic energy into anenvironment within which the vehicle 100 is positioned.

As described above, the acoustic array 102A can include severalspeaker(s) 104, with each speaker in the acoustic array 102A beingcoupled with an output amplifier. Each amplifier can include a gaininput and a signal input. The processor(s) 106 can perform function(s)108 to calculate data representing a gain for the gain input of eachamplifier and can calculate data representing a signal delay for thesignal input of each amplifier. As described above, the processor(s) 106can access and/or or receive speaker data representing information onthe speaker(s) 104 (e.g., from an internal and/or external data source).Responsive to receiving the signal, the processor(s) 106 can perform thefunction(s) 108, based on the speaker data, and can send signals to eachof the speaker(s) 104. Each of the speaker(s) 104 can emit acousticenergy based on the signals, thereby emitting a beam of steered acousticenergy, as illustrated in block 814. The foregoing description oftechniques for emitting a beam of acoustic energy are described in thecontext of a single beam of acoustic energy. However, in additional oralternative examples, the same or similar techniques can be implementedto output any number of beams of acoustic energy, as described abovewith reference to FIGS. 3A and 3B and below with reference to FIG. 9.

Block 816 illustrates determining characteristics of the audiosignal(s). In at least one example, such as where the acousticnotification is associated with a multi-channel output, the audio outputdetermination system 212 can determine a timing for emitting one or moresounds, a volume for emitting one or more sounds, audio characteristics(e.g., a frequency, a volume, a pitch, a tone, a duration, etc.) foremitting one or more sounds, etc. That is, in such an example, the audiooutput determination system 212 can determining a timing, a volume, oraudio characteristics associated with the audio signals(s) such to varythe timing, the volume, or the audio characteristics associated with thesounds output based on the audio signal(s).

Block 818 illustrates sending signal(s) to the acoustic array. In atleast one example, for instance, in when an acoustic notification isassociated with a multi-channel output, the audio output determinationsystem 212 can send multiple signals that can be output by differentchannels(s) of speakers in different ways. For instance, with referenceto FIG. 4, the audio output determination system 212 can send a firstsignal 400A to a first group of speaker(s) 402A, a second signal 400B tothe second group of speaker(s) 402B, and so on. Each signal 400A-400Ncan include data indicating an audio signal, a time associated withoutputting the audio signal, a volume associated with outputting theaudio signal, audio characteristics associated with outputting the audiosignal, etc. In at least one example, individual signals (e.g., signal400A, signal 400B, etc.) can be associated with a same audio signal ordifferent audio signals, which can be associated with a same digitalaudio file. That is, in at least one example, each signal 400A-400N canbe associated with an audio signal that, when collectively emitted,comprises an acoustic notification corresponding to a digital audiofile. Responsive to receiving the signals 400, each group of speakers402A-402N can emit a sound. In at least one example, responsive toreceiving a signal 400A, the first group of speaker(s) 402A can a sound404A, responsive to receiving a signal 400B, the second group ofspeaker(s) 402B can emit a sound 404B, and so on. That is, responsive toreceiving the signals 400, the individual channels of the multi-channelconfiguration can cause sounds to be emitted by one or more speaker(s)of the acoustic array 102A, as illustrated in block 820.

Returning to block 804, responsive to determining that a trigger eventhas not occurred, the audio output determination system 212 can continueto receive and analyze sensor data and/or data received from one or moreother systems of the vehicle 100 to determine an occurrence of a triggerevent. That is, the audio output determination system 212 can await atrigger event, as illustrated in block 822.

FIG. 9 illustrates a flow diagram illustrating another example process900 for causing beams of acoustic energy to be emitted by speakers of anacoustic array.

Block 902 illustrates receiving, at an acoustic array, a signal (e.g., acontrol signal) associated with an acoustic notification. As describedabove, in at least one example, the audio output determination system212 can send a signal to one or more acoustic arrays 102. In at leastone example, the signal can be associated with a trigger signal and caninclude data such as an audio signal selected, direction(s) ofpropagation for emitting one or more beams (e.g., the first beam 304Aand the second beam 304B) of acoustic steered energy, and/or a timing(e.g., frequency) for emitting the one or more beams of acoustic steeredenergy. In such an example, the acoustic array 102A can receive thesignal. For instance, in at least one example, the processor(s) 106 canreceive the signal.

In at least one example, the signal can indicate that the acousticnotification corresponds to a multi-beam output wherein a first beam ofacoustic energy is emitted at a first time and a second beam of acousticenergy is emitted at a second time. In at least one example, an amountof time between the first time and the second time can be indicated inthe signal. In at least one example, the first time and the second timecan be output with a time delay (e.g., 100 ms, etc.) such that the firstbeam of acoustic energy and the second beam of acoustic energy areperceived by the target object to be contiguous.

In at least one example, the first beam of acoustic energy is offsetfrom the second beam of acoustic energy, as described below. That is, inat least one example, the first beam of acoustic energy can beassociated with a first direction of propagation and the second beam ofacoustic energy can be associated with a second direction ofpropagation. In some examples, angles between directions of propagationcan be determined based on an extent of a target object (e.g., height,length, width, etc.), a pose of a target object (e.g., position,orientation, etc.), a distance between the target object and the vehicle100, an angle of the target object relative to the vehicle 100 (e.g.,angle from a normal of the vehicle 100), a type of message to becommunicated, etc. In at least one example, the first direction ofpropagation and the second direction of propagation can be included inthe signal.

Block 904 illustrates receiving speaker data associated with speaker(s)of the acoustic array. In at least one example, the processor(s) 106 ofthe acoustic array 102A can access and/or or receive data (e.g., speakerdata) representing information on the speaker(s) 104 (e.g., from aninternal and/or external data source) and the information can include,but is not limited to, array width, speaker spacing in the acousticarray 102A, a wave front distance between adjacent speakers in theacoustic array 102A, a number of speakers in the acoustic array 102A,speaker characteristics (e.g., frequency response, output level per wattof power, etc.), etc.

Block 906 illustrates performing, based at least in part on the signaland the speaker data, function(s) to generate signals for individualspeakers of the acoustic array. In at least one example, theprocessor(s) 106 can implement function(s) 108 to operate the acousticarray 102A, as described above. The function(s) 108 can be implementedin hardware, software, or a combination thereof (e.g., processor(s) 106,computer-readable media executable by the processor(s) 106, etc.), andthe function(s) 108 implemented can include, but are not limited to, adelay calculator, a gain calculator, a beam steering algorithm, anadaptive beam steering algorithm, an environment compensator, an audiosignal modulator, an ambient noise compensator, and a signal converter.Furthermore, in some examples, the processor(s) 106 can utilizeadditional or alternative signal(s), such as object pose, microphonesignal(s), environmental signal(s), audio signals, etc. for determininghow to emit the beams of steered acoustic energy for effectuating theacoustic notification.

In at least one example, when the acoustic array 102A is in an arbitraryarray configuration, the processor(s) 106 can utilize the function(s)108 described above; however, the function(s) 108 can additionallyinclude Lagrange filter coefficients as applied to gains and a taperfunction (e.g., Nuttall), which can be centered in a direction of abeam, to determine time delays for outputting audio signals.

Block 908 illustrates sending the signals to the individual speakers.Based at least in part on performing the function(s) 108, theprocessor(s) 106 can send individual signals to one or more of thespeakers 104. In at least one example, an individual signal can indicateat least a gain for the gain input of an individual amplifier and datarepresenting a signal delay for the signal input of the amplifier. In atleast one example, the processor(s) 106 can send a first set of signalscorresponding to a first beam of acoustic energy and a second set ofsignals corresponding to a second beam of acoustic energy.

Block 910 illustrates causing, based at least in part on the signals,the individual speakers to emit a first beam of acoustic energyassociated with the acoustic notification at a first time. In at leastone example, the speaker(s) 104 can emit acoustic energy based on afirst group of signals corresponding to a first beam of acoustic energy,thereby emitting a first beam of steered acoustic energy. The speaker(s)104 can emit the first beam of steered acoustic energy associated with aparticular audio signal in a first direction of propagation at a firsttime based on the first set of signals received from the processor(s)106.

Block 912 illustrates causing, based at least in part on the signals,the individual speakers to emit a second beam of acoustic energyassociated with the acoustic notification at a second time. In at leastone example, the speaker(s) 104 can emit acoustic energy based on asecond group of signals corresponding to a second beam of acousticenergy, thereby emitting a second beam of steered acoustic energy. Thespeaker(s) 104 can emit the second beam of steered acoustic energyassociated with a particular audio signal in a second direction ofpropagation at a second time based on the second set of signals receivedfrom the processor(s) 106.

Returning to FIG. 3, in at least one example, the acoustic array 102Acan emit the first beam 304A indicative of the data representing theselected audio signal (e.g., the acoustic energy reproduces the soundencoded in the audio signal), along the first direction of propagationat the first time (T₀), and can emit the second beam 304B indicative ofthe data representing the selected audio signal, along the seconddirection of propagation at the second time (T₁). That is, at least aportion of the speaker(s) 104 can emit the first beam 304A indicative ofthe data representing the selected audio signal (e.g., the acousticenergy reproduces the sound encoded in the audio signal), along thefirst direction of propagation at the first time (T₀), and at least aportion of the speaker(s) 104 can emit the second beam 304B indicativeof the data representing the selected audio signal, along the seconddirection of propagation at the second time (T₁). In some examples, theportions of speaker(s) 104 can be the same speakers in the acoustic beamforming array 102A and, in other examples, the portions of speaker(s)104 can be different speakers in the acoustic beam forming array 102A.In any of the examples described herein, emitting the first beam 304A atthe first time and the second beam 304B at a second time may comprise(i.e., comprises in some examples) sweeping from the first direction tothe second direction (e.g., in a continuous or discrete manner).

Block 914 illustrates determining whether a subsequent signal (e.g.,control signal) is received. In some examples, the audio outputdetermination system 212 can send one or more subsequent signals 214 tothe acoustic array 102A to cause the speaker(s) 104 oscillate betweenemitting the first beam 304A and the second beam 304B in theirrespective directions of propagation at a defined frequency (e.g., 10 Hzor 100 ms) such that the acoustic notification is perceived by thepedestrian 302 as moving side to side (e.g., wiggling) for a sustainedamount of time. In such examples, the audio output determination system212 can determine a frequency for sending the subsequent signals, whichcorresponds to a rate at which the first beam 304A and the second beam304B are subsequently emitted from the one or more acoustic arrays 102.That is, in at least one example, the audio output determination system212 can determine a frequency at which the pedestrian 302 hears theacoustic notification move from side to side repeatedly and subsequentbeams of steered acoustic energy can be output in the first direction ofpropagation and the second direction of propagation at such frequency.In at least one example, the subsequent signals can include updateddirections of propagation and or timing, which can be based on updatedsensor data 202 received by the vehicle computing device(s) 204. Thatis, as the vehicle 100 and/or the pedestrian 302 move, the audio outputdetermination system 212 can update the directions of propagation and/ortiming at which additional beams of acoustic energy are to be output bythe acoustic array 102A.

Based at least in part on determining that a subsequent signal has beenreceived, process 900 can return to block 906 to repeat the process withthe subsequent signal to cause the speaker(s) 104 to emit additionalbeams of acoustic energy (e.g., in their respective directions ofpropagation and at their respective times) continuously such that theacoustic notification is perceived by the target object as moving sideto side (e.g., wiggling) for a sustained amount of time.

Block 916 illustrates determining that the acoustic notification iscomplete. If the acoustic array 102A does not receive subsequentsignals, it can determine that the acoustic notification is complete.

FIG. 10 illustrates a flow diagram illustrating yet another exampleprocess 1000 for causing sounds to be emitted by speakers of an acousticarray for an acoustic notification.

Block 1002 illustrates receiving, at an acoustic array, signals (e.g.,control signals) associated with an acoustic notification, individual ofthe signals corresponding to individual channels in a multi-channelspeaker configuration. As described above, in at least one example, theaudio output determination system 212 can send signals to one or moreacoustic arrays 102. In at least one example, each of the signals can beassociated with a trigger signal and can include data such as an audiosignal selected, a timing for emitting one or more sounds associatedwith the audio signal, volume associated with emitting one or moresounds associated with the audio signal, audio characteristicsassociated with emitting the one or more sounds associated with theaudio signal, etc. In such an example, the acoustic array 102A canreceive the signals. In at least one example, each signal can be sent toa different channel in a multi-channel speaker configuration.

Block 1004 illustrates sending a first signal of the signals to thegroup of speakers associated with a first channel of the multi-channelconfiguration. Based at least in part on receiving the signals, theprocessor(s) 106 can send a first signal of the signals to a firstchannel of a multi-channel speaker configuration. In at least oneexample, the processor(s) 106 can perform one or more of the function(s)108 prior to sending the first signal to the first channel.

Block 1006 illustrates sending a second signal of the signals to thegroup of speakers associated with a second channel of the multi-channelconfiguration. Based at least in part on receiving the signals, theprocessor(s) 106 can send a second signal of the signals to a secondchannel of a multi-channel speaker configuration. In at least oneexample, the processor(s) 106 can perform one or more of the function(s)108 prior to sending the second signal to the second channel.

Block 1008 illustrates causing, based at least in part on the firstsignal, the group of speakers associated with the first channel to emita first sound. In at least one example, the speaker(s) 104 correspondingto the first channel can emit a first sound based on the first signal.

Block 1010 illustrates causing, based at least in part on the secondsignal, the group of speakers associated with the second channel to emita second sound. In at least one example, the speaker(s) 104corresponding to the second channel can emit a second sound based on thesecond signal. As described above with reference to FIGS. 5A-5D, in atleast one example, the individual channels can output sounds atdifferent times, at different volumes, with different audiocharacteristics, etc. to cause the sounds to be output dynamically. Insome examples, the sounds can be the same audio signal or differentaudio signals.

Block 1012 illustrates determining whether subsequent signals (e.g.,control signals) are received. In some examples, the audio outputdetermination system 212 can send one or more subsequent signals to theacoustic array 102A to cause the speaker(s) 104 to emit additionalsounds such that the acoustic notification is emitted for a sustainedamount of time. Based at least in part on determining that a subsequentsignal has been received, process 1100 can return to block 1104 torepeat the process with the subsequent signal to cause the speaker(s)104 to emit additional sounds such that the acoustic notification isemitted for a sustained amount of time. In such examples, the audiooutput determination system 212 can determine a frequency for sendingthe subsequent signals, which corresponds to a rate at which theadditional sounds are subsequently emitted from the acoustic array 102A.In an alternate example, the signals can include instructions tocontinuously emit the additional sounds such that the acousticnotification is output for a sustained amount of time (e.g., which cancorrespond to a predetermined period of time or the receipt of a stopsignal).

Block 1014 illustrates determining that the acoustic notification iscomplete. If the acoustic array 102A does not receive subsequentsignals, it can determine that the acoustic notification is complete.

As noted above, wherein an acoustic array is identified as acousticarray 102A, any other acoustic array 102B-102N can be used for emittingparticular beams of acoustic energy.

The various techniques described herein can be implemented in thecontext of computer-executable instructions or software, such as programmodules, that are stored in computer-readable storage and executed bythe processor(s) of one or more computers or other devices such as thoseillustrated in the figures. Generally, program modules include routines,programs, objects, components, data structures, etc., and defineoperating logic for performing particular tasks or implement particularabstract data types.

Other architectures can be used to implement the describedfunctionality, and are intended to be within the scope of thisdisclosure. Furthermore, although specific distributions ofresponsibilities are defined above for purposes of discussion, thevarious functions and responsibilities might be distributed and dividedin different ways, depending on circumstances.

Similarly, software can be stored and distributed in various ways andusing different means, and the particular software storage and executionconfigurations described above can be varied in many different ways.Thus, software implementing the techniques described above can bedistributed on various types of computer-readable media, not limited tothe forms of memory that are specifically described.

Example Clauses

A. A system comprising: a sensor; an acoustic array disposed on anexterior surface of a vehicle, the acoustic array comprising a pluralityof speakers configured to output audio; one or more processors; and oneor more non-transitory computer-readable media storing instructionsthat, when executed by the one or more processors, cause the system toperform operations comprising: receiving, from the sensor, sensor dataindicative of a pedestrian; determining, based at least in part on thesensor data, a pedestrian position; determining, based at least in parton the sensor data, a first direction of propagation to emit a firstbeam of acoustic energy, the first direction of propagation directingthe first beam of acoustic energy towards a first position relative tothe pedestrian position; causing, at a first time, at least a firstportion of the plurality of speakers to emit the first beam of acousticenergy indicative of an alert in the first direction of propagation;determining, based at least in part on the sensor data, a seconddirection of propagation to emit a second beam of acoustic energy, thesecond direction of propagation directing the second beam of acousticenergy towards a second position relative to the pedestrian; andcausing, at a second time, at least a second portion of the plurality ofspeakers to emit the second beam of acoustic energy indicative of thealert in the second direction of propagation, the first beam of acousticenergy and the second beam of acoustic energy, when perceived by thepedestrian, enabling the pedestrian to localize the vehicle.

B. The system as paragraph B recites, wherein a difference between thefirst direction of propagation and the second direction of propagationis based at least in part on an extent of the pedestrian.

C. The system as any of paragraphs A-B recite, operations furthercomprise: causing at least a third portion of the plurality of speakersto emit a third beam of acoustic energy indicative of the alert in thefirst direction at a third time; and causing the at least a fourthportion of the plurality of speakers to emit a fourth beam of acousticenergy indicative of the alert in the second direction of propagation ata fourth time.

D. The system as any of paragraphs A-C recite, operations furthercomprising: determining, based at least in part on the sensor data, apredicted intersection point of a pedestrian trajectory of thepedestrian and a vehicle trajectory of the vehicle; and determining thefirst direction of propagation and the second direction of propagationbased at least in part on determining the predicted intersection pointis within a threshold distance of the vehicle.

E. The system as any of paragraphs A-D recite, wherein the plurality ofspeakers are arranged in an arbitrary configuration.

F. One or more non-transitory computer-readable media storinginstructions that, when executed by one or more processors, cause theone or more processors to perform operations comprising: receiving, froma sensor associated with a vehicle, sensor data associated with anobject; determining, based at least in part on the sensor data, firstdata for emitting a first beam of acoustic energy via a first portion ofa plurality of speakers of an acoustic array; determining, based atleast in part on the sensor data, second data for emitting a second beamof acoustic energy via a second portion of the plurality of speakers ofthe acoustic array; causing, at a first time and based at least in parton the first data, the first portion of the plurality of speakers toemit the first beam of acoustic energy in a first direction relative tothe object; and causing, at a second time and based at least in part onthe second data, the second portion of the plurality of speakers to emitthe second beam of acoustic energy in a second direction relative to theobject, the first direction differing from the second direction by anoffset.

G. The one or more non-transitory computer-readable media as paragraph Frecites, wherein the operations further comprise: determining, based atleast in part on the sensor data, a distance between an object positionof the object and a vehicle position of the vehicle, wherein the offsetis based at least in part on the distance.

H. The one or more non-transitory computer-readable media as any ofparagraphs F-G recite, wherein the operations further comprise:determining, based at least in part on the sensor data, an angle betweenan object position of the object and a vehicle position of the vehicle,wherein the offset is based at least in part on the angle.

I. The one or more non-transitory computer-readable media as any ofparagraphs F-H recite, wherein the operations further comprise:determining, as an extent of the object and based at least in part onthe sensor data, one or more of a length, width, or height of theobject, wherein the offset is based at least in part on the extent ofthe object.

J. The one or more non-transitory computer-readable media as any ofparagraphs F-I recite, wherein the first direction is associated with afirst side of the object and the second direction is associated with asecond side of the object.

K. The one or more non-transitory computer-readable media as any ofparagraphs F-J recite, wherein the operations further comprise: causingthe at least the first portion of the plurality of speakers to emit athird beam of acoustic energy in the first direction at a third time;and causing the at least the second portion of the plurality of speakersto emit a fourth beam of acoustic energy in the second direction ofpropagation at a fourth time.

L. The one or more non-transitory computer-readable media as paragraph Krecites, wherein the second time differs from the first time by a delayperiod, the third time differs from the second time by the delay period,and the fourth time differs from the third time by the delay period.

M. The one or more non-transitory computer-readable media as paragraph Krecites, wherein the operations further comprise: receiving, from thesensor, updated sensor data; and updating at least one of the firstdirection of propagation or the second direction of propagation based onthe updated sensor data for emissions of the third or fourth beams ofacoustic energy.

N. A method comprising: receiving, from a sensor associated with avehicle, sensor data associated with an object in an environment of thevehicle; determining, based at least in part on the sensor data, firstdata for emitting a first beam of acoustic energy via a first portion ofa plurality of speakers of an acoustic array associated with thevehicle; determining, based at least in part on the sensor data, seconddata for emitting a second beam of acoustic energy via a second portionof the plurality of speakers of the acoustic array; causing, at a firsttime and based at least in part on the first data, the first portion ofthe plurality of speakers to emit the first beam of acoustic energy at afirst angle relative to the vehicle; and causing, at a second time andbased at least in part on the second data, the second portion of theplurality of speakers to emit the second beam of acoustic energy at asecond angle relative to the vehicle, wherein a difference between thefirst angle and the second angle comprise an offset.

O. The method as paragraph N recites, wherein the object is apedestrian, and wherein the first time and the second time are within athreshold amount of time such that the pedestrian is able to localizethe vehicle.

P. The method as any of paragraphs N-O recite, further comprising:determining, based at least in part on the sensor data, a predictedintersection point of an object trajectory of the object and a vehicletrajectory of the vehicle; determining that the predicted intersectionpoint is within a threshold distance of the vehicle; and determining thefirst data and the second data responsive to determining the predictedintersection point is within the threshold distance of the vehicle.

Q. The method as any of paragraphs N-P recite, further comprising:determining, based at least in part on the sensor data, at least one ofan extent of the object or a pose of the object; determining the firstangle based on at least one of the extent of the object or the pose ofthe object; and determining the second angle based on at least one ofthe extent of the object or the pose of the object.

R. The method as any of paragraphs N-Q recite, further comprising:causing the first portion of the plurality of speakers to emit a thirdbeam of acoustic energy at the first angle at a third time; and causingthe second portion of the plurality of speakers to emit a fourth beam ofacoustic energy at the second angle at a fourth time.

S. The method as any of paragraphs N-R recite, wherein the first timediffers from the second time by a delay period, and wherein the thirdtime differs from the fourth time by the delay period.

T. The method as any of paragraphs N-S recite, further comprising:determining, based at least in part on the sensor data, a distancebetween the object and the vehicle, an angle between the object and thevehicle, or a type of information to be communicated to the object,wherein the offset is based at least in part on the distance between theobject and the vehicle, the angle between the object and the vehicle, orthe type of information to be communicated to the object.

U. A system comprising: an acoustic array disposed on at least oneexterior surface of a vehicle, the acoustic array comprising a pluralityof speakers configured for multi-channel functionality; one or moreprocessors; and one or more non-transitory computer-readable mediastoring instructions that, when executed by the one or more processors,cause the system to perform operations comprising: determining a firstsignal for emitting a first sound via at least a first speaker of theplurality of speakers; determining a second signal for emitting a secondsound via at least a second speaker of the plurality of speakers, thesecond speaker being associated with a different channel than the firstspeaker; causing, based at least in part on the first signal, the firstspeaker to emit the first sound; and causing, based at least in part onthe second signal, the second speaker to emit the second sound, thefirst sound and the second sound being spatialized across the at leastone exterior surface of the vehicle such that, when perceived by apedestrian, the pedestrian is capable of perceiving a surface boundaryof the vehicle.

V. The system as paragraph U recites, wherein the operations furthercomprise: determining a first time to emit the first sound; determininga second time to emit the second sound; causing the first speaker toemit the first sound at the first time; and causing the second speakerto emit the second sound at the second time.

W. The system as paragraph V recites, wherein the first time and thesecond time are a same time.

X. The system as paragraph V recites, wherein the first sound and thesecond sound are same audio signals or different audio signals.

Y. The system as any of paragraphs U-X recite, wherein the operationsfurther comprise: determining a first audio characteristic associatedwith the first sound; and determining a second audio characteristicassociated with the second sound, wherein the first audio characteristicand the second audio characteristic comprise a pitch, a duration, atone, or a timber.

Z. The system as any of paragraphs U-Y recite, wherein the operationsfurther comprise: determining a first volume to emit the first sound;determining a second volume to emit the second sound; causing the firstspeaker to emit the first sound at the first volume; and causing thesecond speaker to emit the second sound at the second volume.

AA. The system as any of paragraphs U-Z recite, wherein the operationsfurther comprise: receiving, from a sensor on the vehicle, sensor dataassociated with an environment of the vehicle; determining, based atleast in part on the sensor data, a velocity of the vehicle; determiningthat the velocity is below a threshold velocity; and causing the firstspeaker to emit the first sound and the second speaker to emit thesecond sound based at least in part on determining that the velocity isbelow the threshold velocity.

AB. The system as paragraph AA recites, wherein the operations furthercomprise causing at least portions of the plurality of speakers todynamically emit sounds until the velocity is determined to meet orexceed the threshold velocity.

AC. A method comprising: determining a plurality of signals fordynamically emitting a plurality of sounds via a plurality of speakersassociated with an acoustic array disposed on a vehicle, wherein eachsignal of the plurality of signals is emitted from at least one speakerof the plurality of speakers that is associated with a particularchannel of a plurality of channels; and causing a portion of theplurality of speakers to dynamically emit the plurality of sounds, theplurality of sounds being spatialized across at least one surface of thevehicle such that, when the plurality of sounds are output via theportion of the plurality of speakers, the plurality of sounds conveyinformation associated with a geometry of the vehicle.

AD. The method as paragraph AC recites, further comprising: determiningaudio characteristics for the plurality of sounds, the audiocharacteristics comprising one or more of a frequency, a volume, apitch, a tone, or a duration; and causing a portion of the plurality ofspeakers to dynamically emit the plurality of sounds based at least inpart on the audio characteristics, wherein at least two sounds of theplurality of sounds have different audio characteristics.

AE. The method as any of paragraphs AC-AD recite, further comprising:determining a timing for emitting the plurality of sounds; and causingat least a portion of the plurality of speakers to dynamically emit theplurality of sounds based at least in part on the timing, wherein atleast two sounds of the plurality of sounds are emitted at differenttimes.

AF. The method as paragraph AE recites, wherein causing the portion ofthe plurality of speakers to dynamically emit the plurality of soundscomprises causing, based at least in part on the different times, theportion of the plurality of speakers to emit the plurality of sounds ina sequence from a first side of the vehicle to a second side of thevehicle.

AG. The method as any of paragraphs AC-AF recite, further comprising:receiving, from a sensor on the vehicle, sensor data associated with anenvironment of the vehicle; determining, based at least in part on thesensor data, a velocity of the vehicle; determining that the velocitydoes not meet or exceed a threshold velocity; and causing the portion ofthe plurality of speakers to dynamically emit the plurality of soundsbased at least in part on determining that the velocity does not meet orexceed the threshold velocity.

AH. The method as paragraph AG recites, further comprising causing theportion of the plurality of speakers to dynamically emit the pluralityof sounds until the velocity is determined to meet or exceed thethreshold velocity.

AI. The method as any of paragraphs AC-AH recite, further comprisingcausing the portion of the plurality of speakers to dynamically emit theplurality of sounds from right to left across the acoustic array,wherein a first speaker associated with a first channel of the pluralityof channels emits a first sound at a first time and a second speakerassociated with a second channel of the plurality of channels emits asecond sound at a second time after the first time, and the firstspeaker is positioned to the right of the second speaker on the acousticarray.

AJ. One or more non-transitory computer-readable media storinginstructions that, when executed by one or more processors, cause theone or more processors to perform acts comprising: determining aplurality of signals configured to cause a plurality of speakersassociated with an acoustic array disposed on a vehicle to emit aplurality of sounds, wherein the plurality of speakers are associatedwith a plurality of channels; and causing, based at least in part on theplurality of signals, a portion of the plurality of speakers to emit theplurality of sounds, the plurality of sounds being spatialized across atleast one surface of the vehicle such that, when perceived by apedestrian proximate the vehicle, the pedestrian is capable ofperceiving an extent of the vehicle, a location of the vehicle, or avelocity of the vehicle.

AK. The one or more non-transitory computer-readable media as paragraphAJ recites, wherein the plurality of signals comprise instructions tovary at least one of an audio characteristic, a timing, or a volume ofindividual sounds of the plurality of sounds.

AL. The one or more non-transitory computer-readable media as any ofparagraphs AJ-AK recite, the acts further comprising: receiving, from asensor on the vehicle, sensor data associated with an environment of thevehicle; determining, based at least in part on the sensor data, avelocity of the vehicle; determining that the velocity does not meet orexceed a threshold velocity; and causing the portion of the plurality ofspeakers to emit the plurality of sounds based at least in part ondetermining that the velocity does not meet or exceed the thresholdvelocity.

AM. The one or more non-transitory computer-readable media as any ofparagraphs AJ-AL recite, the acts further comprising: determining, basedat least in part on the sensor data, the location of the vehicle; andcausing the portion of the plurality of speakers to emit the pluralityof sounds based at least in part on the location.

AN. The one or more non-transitory computer-readable media as any ofparagraphs AJ-AM recite, wherein plurality of sounds are emittedsequentially from a first speaker proximate a first side of the acousticarray to a last speaker at a second side of the acoustic array.

AO. While paragraphs A-E and U-AB are described above with respect to asystem, it is understood in the context of this document that thecontent of paragraphs A-E and/or U-AB may also be implemented via amethod, device, and/or computer storage media. While paragraphs N-T andAC-AI are described above with respect to a method, it is understood inthe context of this document that the content of paragraphs N-T and/orAC-AI may also be implemented via a system, device, and/or computerstorage media. While paragraphs F-M and AJ-AN are described above withrespect to a non-transitory computer-readable medium, it is understoodin the context of this document that the content of paragraphs F-Mand/or AJ-AN may also be implemented via a method, device, and/orsystem.

CONCLUSION

While one or more examples of the techniques described herein have beendescribed, various alterations, additions, permutations and equivalentsthereof are included within the scope of the techniques describedherein.

In the description of examples, reference is made to the accompanyingdrawings that form a part hereof, which show by way of illustrationspecific examples of the claimed subject matter. It is to be understoodthat other examples can be used and that changes or alterations, such asstructural changes, can be made. Such examples, changes or alterationsare not necessarily departures from the scope with respect to theintended claimed subject matter. While the steps herein can be presentedin a certain order, in some cases the ordering can be changed so thatcertain inputs are provided at different times or in a different orderwithout changing the function of the systems and methods described. Thedisclosed procedures could also be executed in different orders.Additionally, various computations that are herein need not be performedin the order disclosed, and other examples using alternative orderingsof the computations could be readily implemented. In addition to beingreordered, the computations could also be decomposed intosub-computations with the same results.

What is claimed is:
 1. A system comprising: a sensor; an acoustic arraydisposed on an exterior surface of a vehicle, the acoustic arraycomprising a plurality of speakers configured to output audio; one ormore processors; and one or more non-transitory computer-readable mediastoring instructions that, when executed by the one or more processors,cause the system to perform operations comprising: receiving, from thesensor, sensor data indicative of a pedestrian; determining, based atleast in part on the sensor data, a pedestrian position; determining,based at least in part on the sensor data, a first direction ofpropagation to emit a first beam of acoustic energy, the first directionof propagation directing the first beam of acoustic energy towards afirst position on a first side of the pedestrian position; causing, at afirst time, at least a first portion of the plurality of speakers toemit the first beam of acoustic energy indicative of an alert in thefirst direction of propagation; determining, based at least in part onthe sensor data, a second direction of propagation to emit a second beamof acoustic energy, the second direction of propagation directing thesecond beam of acoustic energy towards a second position on a secondside of the pedestrian position; and causing, at a second time, at leasta second portion of the plurality of speakers to emit the second beam ofacoustic energy indicative of the alert in the second direction ofpropagation, the first beam of acoustic energy and the second beam ofacoustic energy, when perceived by the pedestrian, enabling thepedestrian to localize the vehicle.
 2. The system as claim 1 recites,wherein a difference between the first direction of propagation and thesecond direction of propagation is based at least in part on an extentof the pedestrian.
 3. The system as claim 1 recites, operations furthercomprising: causing at least a third portion of the plurality ofspeakers to emit a third beam of acoustic energy indicative of the alertin the first direction at a third time; and causing at least a fourthportion of the plurality of speakers to emit a fourth beam of acousticenergy indicative of the alert in the second direction of propagation ata fourth time.
 4. The system as claim 1 recites, operations furthercomprising: determining, based at least in part on the sensor data, apredicted intersection point of a pedestrian trajectory of thepedestrian and a vehicle trajectory of the vehicle; and determining thefirst direction of propagation and the second direction of propagationbased at least in part on determining the predicted intersection pointis within a threshold distance of the vehicle.
 5. The system as claim 1recites, wherein the plurality of speakers are arranged in an arbitraryconfiguration.
 6. One or more non-transitory computer-readable mediastoring instructions that, when executed by one or more processors,cause the one or more processors to perform operations comprising:receiving, from a sensor associated with a vehicle, sensor dataassociated with an object; determining, based at least in part on thesensor data, first data for emitting a first beam of acoustic energy viaa first portion of a plurality of speakers of an acoustic array;determining, based at least in part on the sensor data, second data foremitting a second beam of acoustic energy via a second portion of theplurality of speakers of the acoustic array; causing, at a first timeand based at least in part on the first data, the first portion of theplurality of speakers to emit the first beam of acoustic energy in afirst direction proximate a first side of the object; and causing, at asecond time and based at least in part on the second data, the secondportion of the plurality of speakers to emit the second beam of acousticenergy in a second direction proximate a second side of the object, thefirst direction differing from the second direction by an offset.
 7. Theone or more non-transitory computer-readable media as claim 6 recites,wherein the operations further comprise: determining, based at least inpart on the sensor data, a distance between an object position of theobject and a vehicle position of the vehicle, wherein the offset isbased at least in part on the distance.
 8. The one or morenon-transitory computer-readable media as claim 6 recites, wherein theoperations further comprise: determining, based at least in part on thesensor data, an angle between an object position of the object and avehicle position of the vehicle, wherein the offset is based at least inpart on the angle.
 9. The one or more non-transitory computer-readablemedia as claim 6 recites, wherein the operations further comprise:determining, as an extent of the object and based at least in part onthe sensor data, one or more of a length, width, or height of theobject, wherein the offset is based at least in part on the extent ofthe object.
 10. The one or more non-transitory computer-readable mediaas claim 6 recites, wherein the operations further comprise: causing theat least the first portion of the plurality of speakers to emit a thirdbeam of acoustic energy in the first direction at a third time; andcausing the at least the second portion of the plurality of speakers toemit a fourth beam of acoustic energy in the second direction at afourth time.
 11. The one or more non-transitory computer-readable mediaas claim 10 recites, wherein the second time differs from the first timeby a delay period, the third time differs from the second time by thedelay period, and the fourth time differs from the third time by thedelay period.
 12. The one or more non-transitory computer-readable mediaas claim 10 recites, wherein the operations further comprise: receiving,from the sensor, updated sensor data; and updating at least one of thefirst direction or the second direction based on the updated sensor datafor emissions of the third or fourth beams of acoustic energy.
 13. Theone or more non-transitory computer-readable media as claim 6 recites,wherein the offset is associated with a dimension of the object.
 14. Amethod comprising: receiving, from a sensor associated with a vehicle,sensor data associated with an object in an environment of the vehicle;determining, based at least in part on the sensor data, first data foremitting a first beam of acoustic energy via a first portion of aplurality of speakers of an acoustic array associated with the vehicle;determining, based at least in part on the sensor data, second data foremitting a second beam of acoustic energy via a second portion of theplurality of speakers of the acoustic array; causing, at a first timeand based at least in part on the first data, the first portion of theplurality of speakers to emit the first beam of acoustic energy at afirst angle relative to the vehicle; and causing, at a second time andbased at least in part on the second data, the second portion of theplurality of speakers to emit the second beam of acoustic energy at asecond angle relative to the vehicle, wherein a difference between thefirst angle and the second angle comprise an offset that is associatedwith a dimension of the object.
 15. The method as claim 14 recites,wherein the object is a pedestrian, and wherein the first time and thesecond time are within a threshold amount of time such that thepedestrian is able to localize the vehicle.
 16. The method as claim 14recites, further comprising: determining, based at least in part on thesensor data, a predicted intersection point of an object trajectory ofthe object and a vehicle trajectory of the vehicle; determining that thepredicted intersection point is within a threshold distance of thevehicle; and determining the first data and the second data responsiveto determining the predicted intersection point is within the thresholddistance of the vehicle.
 17. The method as claim 14 recites, furthercomprising: determining, based at least in part on the sensor data, atleast one of an extent of the object or a pose of the object;determining the first angle based on at least one of the extent of theobject or the pose of the object; and determining the second angle basedon at least one of the extent of the object or the pose of the object.18. The method as claim 14 recites, further comprising: causing thefirst portion of the plurality of speakers to emit a third beam ofacoustic energy at the first angle at a third time; and causing thesecond portion of the plurality of speakers to emit a fourth beam ofacoustic energy at the second angle at a fourth time.
 19. The method asclaim 18 recites, wherein the first time differs from the second time bya delay period, and wherein the third time differs from the fourth timeby the delay period.
 20. The method as claim 14 recites, furthercomprising: determining, based at least in part on the sensor data, adistance between the object and the vehicle, an angle between the objectand the vehicle, or a type of information to be communicated to theobject, wherein the offset is based at least in part on the distancebetween the object and the vehicle, the angle between the object and thevehicle, or the type of information to be communicated to the object.